KR101967876B1 - Composite materials for cathode materials in secondary battery, method of manufacturing the same and lithium secondary battery including the same - Google Patents

Abstract

A composite material for a secondary battery positive electrode material, a method for producing the same, and a lithium secondary battery comprising the same. Secondary battery positive electrode material composite for is expressed as carbon particles, and the general formula A _x D _y, charge carriers, ions comprising the charge carrier-ion compound particles dispersed on the surface of the carbon particles, compounds with carbon composite material, the general formula M _z R &_lt; _{w &} gt ;. In the above general formula A _x D _y and _{M z R w A, D,} M, R, and x, y, z, w are described in the detailed description of the invention.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a composite material for a cathode material for a secondary battery, a method for producing the same, and a lithium secondary battery including the composite material,

A secondary battery positive electrode material composite, a manufacturing method thereof, and a lithium secondary battery including the same.

A secondary battery is a battery capable of continuously repeating charging and discharging. A secondary battery is operated by the phenomenon of electron transfer due to a reversible redox reaction through an electrolyte between two electrodes having a large difference in ionization tendency.

Of the secondary batteries, a lithium secondary battery is generally used, and a lithium transition metal compound including both lithium and a transition metal is used as a cathode material of such a lithium secondary battery. Accordingly, various lithium transition metal compounds have been proposed as candidates for a cathode material used in a secondary battery. In the lithium transition metal compound, lithium carries charges through the electrolyte, and the transition metal provides electrons necessary for the reaction through a redox reaction.

In general, the lithium transition metal compound should contain a specific crystal structure composed of a transition metal and charge carrier ions (Li ions), and should have an energy level suitable for using a lithium transition metal compound as an anode.

Examples of such a specific crystal structure include a LiMO ₂ -based layered compound, a LiM ₂ O ₄ -based spinel, and an LiBPO ₄ -based olivine compound. When the above conditions are satisfied, Li ions are inserted into the crystal structure, And / or tear down, thereby functioning as the anode of the secondary battery.

However, since only a part of the material group satisfying all of these conditions exist in the natural world, the width of the usable anode material is limited. Therefore, there is a need for the development of a novel cathode material which can have a high energy density without satisfying the existing anode material conditions.

The present invention also provides a composite material for a cathode material for a secondary battery, which can be used as a cathode active material, and which does not satisfy the existing cathode material conditions, a method for manufacturing the same, and a lithium secondary battery comprising the same.

According to one embodiment, a charge carrier ionic compound-carbon composite comprising carbon particles and charge carrier ionic compound particles represented by the general formula A _x D _y and dispersed on the surface of the carbon particles; And a transition metal compound represented by the general formula M _z R _w .

Wherein A is selected from Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr and Ba; D is F, O, N, Cl, S, P, Br, Se, I, , is selected from (CO _3), wherein M is Fe, Mn, V, Co, Ni, Cu, Ti, Nb, Mo, Y, Ag, Hf, selected from Ta, wherein R is O, C, F, S, Cl, Se, I, N, H, (NO 3), (PO 4), (SO 4), (P 2 O 7), (SiO 4), (CO 3), (BO 3), ( SO ₄ F), 0 <x? 3, 0 <y? 2, 0 <z? 4 and 0 <w?

The charge carrier ionic compound-carbon composite and the transition metal compound may have phases different from each other.

Each of the charge carrier ionic compound particles and the carbon particles is a nano-sized particle. In the charge carrier ionic compound-carbon composite, the charge carrier ionic compound particles may be evenly mixed with the carbon particles.

The charge carrier ionic compound-carbon composite may be distributed at least adjacent to the surface of the transition metal compound.

The charge carrier ionic compound particles may be mainly distributed in a region adjacent to the surface of the transition metal compound.

The carbon particles may be amorphous carbon particles.

The particle size of the carbon particles may be 10 nm to 100 nm.

The charge carrier ionic compound particles may include a first particle having crystallinity and an amorphized second particle.

The particle size of the charge carrier ionic compound particles may be from 5 nm to 100 nm.

The charge carriers ionic compound particles, _{LiF, Li 2 O, Li 3} N, LiI, LiCl, Li 2 S, LiOH, Li 2 CO 3, LiBr, Li 3 PO 4, Li 4 P 2 O 7, Li 2 SO 4 , Li ₂ CO ₃ , Li ₄ SiO ₄ , Li ₂ O ₂ , KF, and NaF.

The transition metal compound may have crystallinity.

The transition metal compound is _{MnO, Mn 2 O 3, Mn} 3 O 4, CoO, Co 3 O 4, FeO, Fe 2 O 3, Fe 3 O 4, V 2 O 5, NiO, Nb 2 O 5, MoO 3 , FeF _3, and the like.

Meanwhile, as a method for producing a composite for a secondary battery anode material according to an embodiment, a charge carrier ionic compound precursor and a carbon precursor are mixed using a mechanochemical reaction to form the charge carrier ionic compound-carbon composite And a step of adding the transition metal compound to the charge carrier ionic compound-carbon composite, wherein the transition metal compound is added to the charge carrier ionic compound-carbon composite.

The mechanochemical reaction may be performed using a high-energy ball mill method.

The transition metal compound may be further added with at least one of a binder, a conductive material and a solvent.

And mixing the charge carrier ionic compound-carbon composite and the transition metal compound using physical stirring.

Other embodiments, on the other hand, include electrolytes; cathode; And a charge carrier ionic compound compound represented by the general formula A _x D _y and containing charge carrier ionic compound particles dispersed on the surface of the carbon particles, and a transition represented by the general formula M _z R _w A positive electrode comprising a metal compound; And a separator.

Wherein A is selected from Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr and Ba; D is F, O, N, Cl, S, P, Br, Se, I, , is selected from (CO _3), wherein M is Fe, Mn, V, Co, Ni, Cu, Ti, Nb, Mo, Y, Ag, Hf, selected from Ta, wherein R is O, C, F, S, Cl, Se, I, N, H, (NO 3), (PO 4), (SO 4), (P 2 O 7), (SiO 4), (CO 3), (BO 3), ( SO ₄ F), 0 <x? 3, 0 <y? 2, 0 <z? 4 and 0 <w?

The positive electrode may oxidize the charge carrier ions on the surface of the transition metal compound, and the reduction reaction may be performed.

In the charged state of the lithium secondary battery, the charge carrier ionic compound is separated into a charge carrier ion and an anion, and the anion can chemically bond with the transition metal compound.

The anion may be mainly distributed on the surface of the transition metal compound.

The present invention can provide a composite material for a secondary battery positive electrode material which can be used as a positive electrode active material even if the requirements of the existing positive electrode material are not satisfied, and a lithium secondary battery including the same.

In addition, the above-described composite material for a cathode material can be produced by a relatively simple method.

FIG. 1 schematically shows a composite for a secondary battery anode material according to an embodiment,
2 shows an STEM (scanning transmission electron microscopy) image of a LiF-C composite according to Preparation Example,
FIG. 3 and FIG. 4 show a part of FIG. 2 highlighted for each internal element of the LiF-C composite. FIG. 3 shows C and FIG. 4 shows F, respectively,
Figure 5 shows the dark field image of the LiF-C composite according to Preparation Example,
FIG. 6 shows an XRD graph of LiF-C composite according to Preparation Example, together with an XRD graph of graphite powder, initial graphite powder, and initial LiF powder treated by high energy ball milling,
7 is a TEM (transmission electron microscopy) image of a cathode material in Example 1,
FIGS. 8 to 11 show mapping of the TEM image of FIG. 7 for each internal element of the composite material for a secondary battery. FIG. 8 shows C, FIG. 9 shows Li, FIG. 10 shows F, Respectively,
12 is an enlarged view of the periphery of MnO in the anode when the anode made of the cathode material according to Example 7 is in a charged state,
13 is an image showing the result of EELS (electron energy loss spectroscopy) analysis on the core and the surface of MnO 2 when the positive electrode made of the positive electrode material according to Example 7 is in a charged state,
14 is an enlarged view of the vicinity of the inner MnO of the anode when the anode made of the cathode material according to Example 7 is in a discharged state,
15 is an image showing the result of EELS analysis on the core and the surface of MnO when the anode made of the positive electrode material according to Example 7 is in a discharged state,
16 is a graph showing the LiF-C + Mn ₃ O ₄ composite electrochemical activity of the anode for a variety of average particle diameter of the Mn ₃ O _4,
17 to 19 are graphs showing electrochemical activities of the positive electrode made of the positive electrode material according to Examples 7 to 9, respectively,
20 and 21 are graphs showing the change of A / A ^{m +} according to the voltage change of the anode made of the positive electrode material according to Example 10 and Example 11, respectively,
22 is a graph showing an electrochemical activity of a positive electrode made of a positive electrode material according to Comparative Example 3. Fig.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, exemplary embodiments of the present invention will be described in detail so as to enable those skilled in the art to easily carry out the present invention. However, the present invention can be implemented in various different forms and is not limited to the embodiments described herein.

The terms used in the embodiments are intended to illustrate specific embodiments and are not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In this specification, the terms "comprises" or "having" and the like refer to the presence of stated features, integers, steps, operations, elements, parts, or combinations thereof, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations thereof.

Hereinafter, embodiments of the present invention will be described in detail. However, it should be understood that the present invention is not limited thereto, and the present invention is only defined by the scope of the following claims.

In the present invention, there is a method of expressing the average size of the population by numerical value by the measurement method in the present invention. However, it is generally used that the mode diameter indicating the maximum value of the distribution and the median value of the integral distribution curve (Number average, length average, area average, mass average, volume average, etc.), and in the present invention, unless otherwise specified, the average particle diameter is a number average diameter, and D50 (distribution ratio is 50% The particle diameter of the point at which it is formed).

FIG. 1 schematically shows a composite for a secondary battery anode material according to one embodiment.

Referring to FIG. 1, a composite for a secondary battery anode material according to an embodiment includes a charge carrier ionic compound-carbon composite 10, and a transition metal compound 20.

The charge carrier ionic compound-carbon composite 10 and the transition metal compound 20 may have phases different from each other. For example, the charge carrier ionic compound-carbon composite 10 may have a phase close to a random-shape, and the transition metal compound 20 may have a predetermined granularity, or a crystal phase .

In one embodiment, the charge carrier ionic compound-carbon composite 10 and the transition metal compound 20 may be physically mixed. That is, as long as the charge carrier ionic compound-carbon composite material 10 and the transition metal compound 20 do not contain weak bonds such as a dispersing force, Van der Waals bond, etc., unless the complex for the secondary battery positive electrode material receives energy from the outside It may be a state in which a strong strong chemical bond is not formed.

On the other hand, in the composite for a secondary battery positive electrode material, the charge carrier ionic compound-carbon composite 10 may surround the surface of the transition metal compound 20 as shown in FIG. That is, the composite for a secondary battery positive electrode material may have a structure in which a transition metal compound 20 is dispersed in a matrix composed of a so-called charge carrier ionic compound-carbon composite material 10.

The charge carrier ionic compound-carbon composite material 10 includes charge carrier ionic compound particles 11 and carbon particles 12. The charge carrier ionic compound-carbon composite material 10 can be obtained by a method in which the carbon particles 12 and the charge carrier ionic compound particles 11 are made into fine particles having a size of several nanometers to several hundreds of nanometers to form charge carrier ionic compound particles 11- 12). The charge carrier ionic compound particles 11 are dispersed on the surface of the carbon particles 12.

In addition, some of the charge carrier ionic compound particles 11 and the carbon particles 12 may be formed as a matrix (matrix) 120 as shown in FIG. That is, the charge carrier ionic compound-carbon composite 10 is prepared by dispersing and compounding the charge carrier ionic compound particles 11 in the carbon matrix 120 in which two or more carbon particles 12 are gathered, Structure.

According to one embodiment, the charge carrier ionic compound particles 11 may be evenly mixed with the carbon particles 12 within the charge carrier ionic compound-carbon composite 10. However, one embodiment is not necessarily limited to the distribution pattern of the carbon particles and the charge carrier ion compound particles, and may have a different distribution pattern depending on the state of the charge carrier ion compound-carbon composite.

The charge carrier ionic compound particles 11 can be represented by the general formula A _x D _y . A may be an element selected from Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr and Ba; D is an element selected from F, O, N, Cl, S, P, Br, OH), (CO ₃ ), or an atom, and 0 <x? 3 and 0 <y? 2.

The charge carrier ionic compound particles 11 may be at least one selected from the group consisting of LiF, Li ₂ O, Li ₃ N, LiI, LiCl, Li ₂ S, LiOH, Li ₂ CO ₃ , LiBr, Li ₃ PO ₄ , Li ₄ P ₂ O ₇ , Li ₂ SO ₄ , Li ₂ CO ₃ , Li ₄ SiO ₄ , Li ₂ O ₂ , KF, and NaF.

The charge carrier ionic compound particles 11 may have an element A and an element or atomic group D forming an ionic bond at a predetermined position in the crystal structure.

In one embodiment, the charge carrier ionic compound particles 11 can comprise first particles 111 having crystallinity and second particles 112 amorphized as shown in Fig. That is, the first particles 111 and the second particles 112 may exist simultaneously in the carbon matrix.

The charge carrier ionic compound particles 11 may have a particle diameter of 1 nm or more, for example, 5 nm or more, for example, 10 nm or more, for example, 15 nm or more, for example, 20 nm or more, For example less than or equal to 90 nm, such as less than or equal to 80 nm, such as less than or equal to 70 nm, such as less than or equal to 60 nm, such as less than or equal to 50 nm, such as less than or equal to 40 nm, For example, not more than 30 nm, for example, not more than 20 nm.

When the particle size of the charge carrier ionic compound particles 11 satisfies the above range, the particles are finely formed, and very small particles can be densely distributed on the surface of the carbon particles 12. Thus, the contact area between the transition metal compound 20 and the charge carrier ionic compound particles 11 can be maximized to improve the performance of the composite material for a secondary battery positive electrode material.

The carbon particles 12 are evenly mixed with the charge carrier ionic compound particles 12 as shown in Fig.

In one embodiment, the carbon particles 12 may be amorphous carbon particles. The carbon particles 12 can be prepared using commercially available carbon-based materials. Examples of the carbon-based material include carbon black, graphite, activated carbon, or a combination thereof.

The carbon particles 12 can increase the conductivity of the carrier ionic compound particles 11 and make the chemical reaction according to the above-mentioned reaction formula 1 occur more easily.

On the other hand, the carbon particles 12 may chemically bond with the anions produced by the charge carrier ionic compound particles 12 in the charging / discharging state of the secondary battery. The electrochemical activity of the carbon particles 12 will be described later.

The carbon particles 12 may have a particle diameter of 1 nm or more, for example, 5 nm or more, for example, 10 nm or more, and may have a particle diameter of 100 nm or less, for example, 90 nm or less, For example, not more than 80 nm, for example, not more than 70 nm, for example, not more than 60 nm, for example, not more than 50 nm.

When the particle size of the carbon particles 12 satisfies the above range, the particles are finely atomized so that the charge carrier ionic compound particles 11 can be densely distributed on the surface of the carbon particles 12, 20 and the charge carrier ionic compound particles 11 can be maximized to improve the performance of the composite material for a secondary battery anode material.

The transition metal compound (20) can be represented by the general formula M _z R _w . Wherein M may be a transition metal element selected from Fe, Mn, V, Co, Ni, Cu, Ti, Nb, Mo, Y, Ag, Hf and Ta; R is O, C, F, S, Cl, Se , I, N, H, from _{(NO 3), (PO 4} ), (SO 4), (P 2 O 7), (SiO 4), (CO 3), (BO 3), (SO 4 F) Selected element, or atom, and 0 < z < = 4 and 0 &lt;

The transition metal compound (20), for example, _{MnO, Mn 2 O 3, Mn} 3 O 4, CoO, Co 3 O 4, FeO, Fe 2 O 3, Fe 3 O 4, V 2 O 5, NiO, Nb ₂ O ₅ , MoO ₃ , and FeF ₃ .

In one embodiment, the transition metal compound 20 may have crystallinity. That is, the transition metal compound (20) may form an ionic bond at a predetermined position in the crystal structure of the transition metal element (M) and the element or atomic group (R).

The transition metal compound 20 may have single crystal particles containing a transition metal element and an anion disposed at a predetermined position in the crystal structure, or polycrystalline particles containing at least two single crystal particles.

On the other hand, in one embodiment, the particle diameter of the transition metal compound (20) is not particularly limited. That is, the transition metal compound (20) can have a particle diameter in various ranges while maintaining the crystallinity. The transition metal compound 20 may have a particle diameter of, for example, several to several hundred nanometers, and may have a particle diameter of submicron to several hundreds of microns.

Accordingly, the size of the transition metal compound 20 can be variously adjusted depending on the use of the composite material for a secondary battery anode material according to one embodiment, the kind of charge carrier ions, and the like.

Hereinafter, a lithium secondary battery including the composite for a secondary battery positive electrode material will be described.

The lithium secondary battery according to an embodiment may include an electrolyte, a cathode, a positive electrode including a composite material for the positive electrode material of the secondary battery, and a separator.

The electrolyte may include a non-aqueous organic solvent and a lithium salt. The non-aqueous organic solvent serves as a medium through which ions involved in the electrochemical reaction of the cell can move. Examples of the non-aqueous organic solvent include carbonate-based, ester-based, ether-based, ketone-based, alcohol-based and aprotic solvents.

Examples of carbonate-based solvents include dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methylpropyl carbonate (MPC), ethyl propyl carbonate (EPC), methylethyl carbonate (MEC), ethylmethyl carbonate (EMC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate , BC), and the like.

Examples of ester solvents include methyl acetate, ethyl acetate, n-propyl acetate, dimethylacetate, methyl propionate, ethyl propionate,? -Butyrolactone, decanolide, valerolactone, Mevalonolactone, caprolactone, and the like.

On the other hand, examples of the ether solvent include dibutyl ether, tetraglyme, diglyme, dimethoxyethane, 2-methyltetrahydrofuran, tetrahydrofuran and the like. Examples of the ketone solvent include cyclohexanone, Examples of the solvent include ethyl alcohol, isopropyl alcohol and the like.

The non-aqueous organic solvent may be used singly or in combination of one or more thereof. When one or more of the non-aqueous organic solvents are mixed, the mixing ratio may be appropriately adjusted according to the performance of the desired secondary battery. The non-aqueous electrolytic solution may further contain additives such as an overcharge inhibitor such as ethylene carbonate, pyrocarbonate and the like.

The lithium salt is dissolved in an organic solvent to act as a source of metal ions in the cell to enable the operation of a basic secondary cell and to promote the movement of metal ions between the anode and the cathode.

A lithium salt _{exemplified, LiPF 6, LiBF 4, LiSbF} 6, LiAsF 6, LiN (SO 3 C 2 F 5) 2, LiC 4 F 9 SO 3, LiClO 4, LiAlO 2, LiAlCl 4, LiN (C x F 2x _{+ 1 SO 2) (C y} F 2y + 1 SO 2) ( where, x and y are natural numbers), LiCl, LiI, LiB ( C 2 O 4) 2 ( lithium bis oxalate reyito borate (lithium bis (oxalato) borate (LiBOB), or a combination thereof.

The negative electrode includes a current collector and a negative electrode active material layer formed on the current collector.

The current collector may be a copper foil, a nickel foil, a stainless steel foil, a titanium foil, a nickel foam, a copper foil, a polymer substrate coated with a conductive metal, or a combination thereof, but is not limited thereto.

The negative electrode active material layer includes a negative electrode active material, a binder, and optionally a conductive material.

The negative electrode active material includes, for example, a substance capable of reversibly intercalating or deintercalating lithium ions, or a transition metal oxide.

As a material capable of reversibly occluding or releasing lithium ions, carbonaceous materials such as carbonaceous anode active materials generally used in lithium secondary batteries and the like can be used. Typical examples thereof include crystalline carbon, amorphous carbon, Can be used. Examples of the crystalline carbon include graphite such as natural graphite or artificial graphite in the form of amorphous, plate-like, flake, spherical or fiber, and examples of the amorphous carbon include soft carbon Carbon) or hard carbon, mesophase pitch carbide, fired coke, and the like.

Examples of the transition metal oxide include vanadium oxide, lithium vanadium oxide, and the like.

The binder serves to attach the negative electrode active material particles to each other well and to adhere the negative electrode active material to the current collector. Examples of the binder include polyvinyl alcohol, carboxymethylcellulose, hydroxypropylcellulose, polyvinyl chloride, carboxylated poly Polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylated styrene, polyvinyl chloride, -Butadiene rubber, epoxy resin, nylon, and the like may be used, but the present invention is not limited thereto.

The conductive material is used for imparting conductivity to the electrode. Any conductive material may be used without causing any chemical change in the battery. Examples of the conductive material include natural graphite, artificial graphite, carbon black, acetylene black, , Carbon-based materials such as carbon fibers; Metal powders such as copper, nickel, aluminum, and silver, or metal-based materials such as metal fibers; Conductive polymers such as polyphenylene derivatives; Or a mixture thereof may be used.

The positive electrode may include a current collector and a composite material for the secondary battery positive electrode material positioned on the current collector, and may further include a binder, a conductive material, and the like.

The constitution of the composite for a cathode material is as described above.

The anode of the lithium secondary battery according to one embodiment may have the oxidation / reduction reaction of the charge carrier ions at the surface of the transition metal compound unlike the conventional anode, but the embodiment is not necessarily limited thereto. The chemical reaction occurring at the anode of the lithium secondary battery according to one embodiment will be described later.

The binder serves to adhere the composite material for a secondary battery positive electrode material to each other and to adhere the composite material for a secondary battery positive electrode material to the current collector well. Examples of the binder include carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, Polybutylene terephthalate, polybutylene terephthalate, hydroxypropylmethylcellulose, polyvinylidene fluoride, polytetrafluoroethylene, polyethylene, polypropylene, styrene-butadiene rubber, polybutadiene, butyl rubber, fluorine rubber, polyethylene oxide, polyvinyl alcohol, And salts thereof, polyvinylpyrrolidone, polyepichlorohydrin, polyphosphazene, polyacrylonitrile, polystyrene, polyvinylpyridine, chlorosulfonated polyethylene, latex, polyester resin, acrylic resin, phenol resin, epoxy resin , Polymers of propylene and olefins of 2 to 8 carbon atoms, (meth) acrylic acid and (meth) And the like copolymers of acrylic acid alkyl esters. However, the embodiment is not limited thereto.

The conductive material is used for imparting conductivity to the electrode, and is not particularly limited as long as it is a material having electron conductivity without causing chemical change in the battery constituted. Examples of the conductive material include natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanotube, and the like. Metal powders such as copper, nickel, And one or more conductive polymers such as polyphenylene derivatives may be used in combination.

The separator separates the negative electrode and the positive electrode and provides a passage for lithium ion, and is not particularly limited as long as it is commonly used in a lithium secondary battery or the like. For example, the separator may have a low resistance to ion movement of the electrolyte and an excellent ability to impregnate the electrolyte. For example, selected from glass fibers, polyester, polyethylene, polypropylene, polytetrafluoroethylene (PTFE), or a combination thereof, and may be nonwoven fabric or woven fabric. For example, in the case of a lithium secondary battery, a polyolefin-based polymer separator such as polyethylene or polypropylene is mainly used. In order to secure heat resistance or mechanical strength, a coated separator containing a ceramic component or a polymer material may be used. Layer structure.

Hereinafter, the principle of operation of a composite for a secondary battery anode material as a cathode in a lithium secondary battery according to one embodiment will be described.

When the lithium secondary battery is in a charged state, the charge carrier ionic compound particles 11 according to one embodiment are separated into A ^{m +} which is a charge carrier ion and D ^{n - which} is an anion.

Here, m and n are natural numbers, and m and n may be the same or different from each other.

That is, the chemical reaction occurring in the charge carrier ion compound particles 11 upon charging can be represented by the following reaction formula (1).

[Reaction Scheme 1]

A _x D _y ? X A ^{m +} + y D ^n-

On the other hand, when the lithium secondary battery is in a charged state, the charge carrier ionic compound particles 11 according to one embodiment can be chemically bonded to the anion D ^{n -} formed from the charge carrier ionic compound particles 11. This chemical reaction can be represented by the following reaction formula (2).

[Reaction Scheme 2]

M _z R _w + D ^{n- -} M _z R _w -D

In one embodiment, since the transition metal compound 20 has crystallinity, the chemical reaction according to the reaction formula 2 is carried out on the surface of the transition metal compound 20. Therefore, when the lithium secondary battery is in a charged state, the charge carrier ionic compound particles 11 are relocated so as to be mainly distributed in a region adjacent to the surface of the transition metal compound 20, and the anion D ^{n -} ) And may be distributed mainly on the surface of the transition metal compound (20). Therefore, when the secondary battery is in a charged state, the transition metal compound 20 can be oxidized by bonding with the anion D ^{n -} .

On the other hand, when the lithium secondary battery is in a discharged state, a reverse reaction of the reaction formula 2 occurs to generate an anion D ^{n -} and recombine with the charge carrier ion A ^{m +} to produce A _x D _y . In this case, the total chemical reaction occurring in the charging / discharging state of the composite material for the secondary battery positive electrode material can be expressed by the reaction formula 3.

[Reaction Scheme 3]

A _x D _y ⇔ x · A ^{m +} + y · M _z R _w -D

Since the chemical reaction according to the Reaction Scheme 3 is reversible, the composite material for the secondary battery anode material according to one embodiment can operate as the anode of the rechargeable battery having the charge / discharge cycle according to the Reaction Formula 3.

According to one embodiment, the transition metal compound, which has been known to have no electrochemical activity as a positive electrode, can be repeatedly subjected to the oxidation / reduction reaction according to the reaction scheme (3). The composite for a secondary battery anode material according to one embodiment can operate as the anode of a secondary battery having a charge / discharge cycle according to the reaction formula (3).

However, the electrochemical activity of the composite material for a cathode material for a secondary battery according to one embodiment is not limited to the above-described reaction formulas. The composite for a secondary battery positive electrode material according to one embodiment can also function as a positive electrode of a lithium secondary battery having a charge / discharge cycle different from the above-described reaction formulas depending on the kind of the transition metal compound 20, for example.

For example, charge carriers, ionic compound particles 11 in accordance with an embodiment is a secondary battery is A ^{m +} to D ⁿ according to the foregoing Scheme 1 when the ^{charge-doedoe} separated, D ^{n -} is the above-mentioned Scheme 2 Can be chemically bonded to the carbon particles (12) other than the transition metal compound (20).

Thereafter, the compound of the carbon particles (12) and the D element can stably maintain the chemical bond even when the secondary battery is repeatedly charged and discharged. That is, C-D having better electronegativity than ordinary carbon may be formed. In this case, C-D can contribute to improvement of performance of the secondary battery.

The overall chemical reaction occurring in the charge / discharge state of the composite material for the secondary battery anode material can be represented by the following equation (4).

[Reaction Scheme 4]

A _x D _y + C + M _z R _w ? X? A ^{m +} + y? CD ⇔ x · AM _z R _w + y · CD

That is, Unlike the above-described Reaction Scheme 3, Reaction Scheme 4 can repeat the oxidation / reduction reaction of A ^{m +} and AM _z R _w . Accordingly, the composite material for a secondary battery positive electrode material according to one embodiment can also function as a positive electrode of a secondary battery having a charge / discharge cycle according to reaction formula (4).

In general, a lithium transition metal compound used as a positive electrode material of a lithium secondary battery should have a specific crystal structure composed of a transition metal and charge carrier ions (Li ion), and have an energy level suitable for use as a positive electrode, The width of the material is limited.

However, the composite for a secondary battery anode material according to one embodiment is not limited to a specific crystal structure or energy level. That is, the complex for a secondary battery cathode material according to an embodiment is composed of a composite in which charge carrier ionic compound particles and carbon particles are combined and a transition metal oxide not containing lithium, and is limited to a specific crystal structure or energy level A new type of cathode material composite.

Therefore, the composite material for a secondary battery anode material according to one embodiment can be used as a cathode material for a variety of materials that could not be used as a conventional anode, for example, manganese oxide and other materials used only as conventional cathode materials.

Hereinafter, a method for manufacturing the above-described composite material for a secondary battery cathode material will be described.

First, a charge carrier ionic compound precursor and a carbon precursor are prepared.

Charge carriers ionic compound precursor, such as comprising at least one selected from LiF, Li ₂ O, Li ₃ N, LiI, LiCl, Li ₂ S, LiOH, Li ₂ CO _3, KF, group containing NaF Granular, or powdered metal salt.

The carbon precursor may be a granular or powdery carbon material comprising at least one selected from the group consisting of hard carbon, soft carbon, graphite, and carbon black.

Thereafter, the prepared charge carrier ionic compound precursor and the carbon precursor are mixed using a mechanochemical reaction, and mechanochemical reaction is carried out, whereby the above-described charge carrier ionic compound compound and carbon precursor are complexed to form a charge carrier ionic compound-carbon To form a complex. The mechanochemical reaction method can be performed using a high-energy ball mill method.

In one embodiment, the weight ratio of the charge carrier ionic compound precursor and the carbon precursor introduced into the high energy ball mill apparatus is, for example, from 1: 0.3 to 1: 3, for example from 1: 0.5 to 1: : May be one. However, the weight ratio is illustrative and may be variously changed depending on the kind of the charge carrier ionic compound and the kind of the transition metal compound to be used.

Through the high energy ball mill, the charge carrier ionic compound precursor can be pulverized into a plurality of charge carrier ionic compound particles and the carbon precursor can be pulverized and finely divided into a plurality of carbon particles, respectively. Also, the charge carrier ionic compound particles and the carbon particles can be uniformly mixed through the high energy ball mill as described above.

On the other hand, the high-energy ball milling process can be performed at room temperature and can be conducted in an air atmosphere or an inert atmosphere such as Ar, Ne, N ₂ .

Thereafter, a process of adding a transition metal compound to the formed charge carrier ionic compound-carbon composite is performed. According to one embodiment, at the time of adding the transition metal compound, at least one of a binder, a conductive material and a solvent may be added together with the transition metal compound.

The binder is for attaching the composite material for secondary battery positive electrode material to each other well, for example, carboxymethylcellulose, hydroxyethylcellulose, hydroxypropylcellulose, hydroxypropylmethylcellulose, polyvinylidene fluoride, polytetrafluoroethylene , Polyethylene, polypropylene, styrene-butadiene rubber, polybutadiene, butyl rubber, fluorine rubber, polyethylene oxide, polyvinyl alcohol, poly (meth) acrylic acid and its salts, polyvinylpyrrolidone, polyepichlorohydrin, poly (Meth) acrylic acid, a copolymer of propylene and an olefin having 2 to 8 carbon atoms, and a copolymer of a (meth) acrylic acid and a (meth) acrylic acid, (Meth) acrylic acid alkyl ester, and the like.

The conductive material used for imparting conductivity to the electrode is not particularly limited as long as it is a material having electron conductivity without causing any chemical change in each of the charge carrier ionic compound-carbon composite material and the transition metal compound. Examples of the conductive material include natural graphite, artificial graphite, carbon black, acetylene black, Ketjen black, carbon fiber, carbon nanotube, and the like. Metal powders such as copper, nickel, And one or more conductive polymers such as polyphenylene derivatives may be used in combination.

Examples of the solvent include NMP (N-methylpyrrolidone), DMF (dimethylformamide), acetone, and the like. Examples of the solvent include a solvent, Dimethylacetamide, or water. These solvents may be used alone or in combination of two or more.

Thereafter, unlike the charge carrier ionic compound-carbon composite forming process described above, the charge carrier ionic compound-carbon composite and the transition metal compound are simply mixed using physical stirring to produce a composite for a secondary battery cathode material according to one embodiment can do.

Hereinafter, embodiments of the present invention will be described in detail with reference to examples. The following examples are for illustrative purposes only and are not intended to limit the scope of the invention.

Manufacturing example : LiF -C composite

A LiF powder (Sigma-Aldrich) having a particle size range of about 1 micron to about 2 microns and a graphite powder (Alfa Aesar) having a particle size range of about 1 micron to about 20 microns were weighed to a weight ratio of 1: 1 Energy ball mill mixing was carried out in a planetary ball mill apparatus (Fritsch, Pulverisette 5) at about 400 rpm for about 48 hours in an Ar atmosphere without a rest period to obtain finely divided LiF particles and LiF -C composite.

Measurement example  One: LiF -C Microstructure of Composite

FIG. 2 shows an STEM (scanning transmission electron microscopy) image of a LiF-C composite according to Preparation Example, and FIGS. 3 and 4 show a portion of FIG. 2 by highlighting the internal elements of the LiF- 3 is indicated by C, and FIG. 4 is indicated by highlighting F, respectively.

Referring to FIG. 2, it can be confirmed that the LiF-C composite has a nearly irregular shape as a whole. 3 and 4, it can be seen that LiF particles and carbon particles are evenly distributed in the LiF-C composite since C and F are superposed and distributed in similar regions.

5 shows the dark field image of the LiF-C composite according to Preparation Example.

In FIG. 5, a bright region shows a signal diffracted from LiF particles. Referring to FIG. 5, it can be confirmed that LiF particles satisfy the above-mentioned particle diameter range.

6 is an XRD graph of a LiF-C composite according to Preparation Example, together with an XRD graph of high energy ball mill treated graphite powder, initial graphite powder, and initial LiF powder.

Referring to FIG. 6, it can be seen that the XRD peak pattern of the LiF-C composite corresponds to the initial LiF powder as a whole, but differs from the initial graphite powder and the high energy ball milled graphite powder. In other words, LiF particles retain the crystallinity in the LiF-C composite, but the graphite powder is somewhat amorphorized by high-energy ball milling.

However, it can be seen that the peak pattern of the LiF-C composite is somewhat wider than that of the initial LiF powder, which shows that the crystallinity of the LiF particles is slightly weaker than that of the initial LiF powder through the high energy ball milling process.

Example  One: LiF -C + Mn ₃ O ₄  Manufacture of composite anode materials (1)

Mn ₃ O ₄ powder synthesized by the hot-injection method and having an average particle size of about 6 nm was added to the LiF-C composite prepared in Production Example, and then, using a planetary ball mill (Fritsch, Pulverisette 23) And the LiF-C + Mn ₃ O ₄ composite cathode material according to Example 1 was prepared by simple mixing.

Measurement example  2: Example  Microstructure of anode material according to

FIG. 7 is a transmission electron microscopy (TEM) image of a cathode material in Example 1, and FIGS. 8 to 11 are mapping images of a TEM image of FIG. 7 for each internal element of a composite material for a cathode of a secondary battery FIG. 8 shows C, FIG. 9 shows Li, FIG. 10 shows F, and FIG. 11 shows Mn.

Referring to FIG. 7, it can be seen that Mn ₃ O ₄ is dispersed in the LiF-C composite matrix according to Example 1, and that the LiF-C composite and Mn ₃ O ₄ are distinguished from each other . Further, it can be confirmed that the LiF-C composite surrounds the surface of Mn ₃ O ₄ .

On the other hand, referring to FIGS. 8 to 11, LiF particles are mixed with carbon particles in the inside of the anode material according to Example 1, but the distribution density is higher on the surface of Mn ₃ O ₄ .

Example  2: LiF -C + Mn ₃ O ₄  Manufacture of composite anode materials (2)

The cathode material of LiF-C + Mn ₃ O ₄ composite according to Example 2 was prepared in the same manner as in Example 1 except that Mn ₃ O ₄ powder having an average particle diameter of about 9 nm was used.

Example  3: LiF -C + Mn ₃ O ₄  Manufacture of composite anode materials (3)

The LiF-C + Mn ₃ O ₄ composite cathode material according to Example 3 was prepared in the same manner as in Example 1, except that Mn ₃ O ₄ powder having an average particle diameter of about 11 nm was used.

Example  4: LiF -C + Mn ₃ O ₄  Manufacture of composite anode materials (4)

The LiF-C + Mn ₃ O ₄ composite cathode material according to Example 4 was prepared in the same manner as in Example 1 except that Mn ₃ O ₄ powder having an average particle size of about 15 nm was used.

Example  5: LiF -C + Mn ₃ O ₄  Manufacture of composite anode materials (5)

The LiF-C + Mn ₃ O ₄ composite cathode material according to Example 5 was prepared in the same manner as in Example 1 except that Mn ₃ O ₄ powder having an average particle diameter of about 18 nm was used.

Example  6: LiF -C + Mn ₃ O ₄  Manufacture of composite anode materials (6)

The LiF-C + Mn ₃ O ₄ composite cathode material according to Example 6 was prepared in the same manner as in Example 1, except that Mn ₃ O ₄ powder having an average particle diameter of about 20 nm was used.

Example  7: LiF -C + MnO  Manufacture of composite anode material

MnO powder (Sigma Aldrich, CAS No. 1344-43-0) having an average particle diameter of about 250 microns was added to the LiF-C composite prepared in the Production Example, and then a planetary ball mill device (Fritsch, Pulverisette 23) To prepare a LiF-C + MnO 2 composite cathode material according to Example 7.

Measurement example  3: Example  7 Change in charge / discharge of anode made of anode material

10 wt% (0.03 g) of a polyacrylonitrile binder, 1 mL of an NMP solvent, and 20 wt% (0.06 g) of a Super P carbon conductive material were mixed with 0.085 g of a LiF-C composite of Example 7, To form a slurry, coating the slurry on an aluminum substrate, and then evaporating the solvent to form a positive electrode made of the positive electrode material according to Example 7.

Thereafter, a counter electrode including the positive electrode and the lithium metal is used to fabricate a half-cell. The half-cell is a non-aqueous electrolyte: has a separation membrane including a (the EC and DMC 1 is mixed and 1M LiPF ₆ in a volume ratio of 1 included), and a polymer membrane.

The positive electrode made of the positive electrode material of Example 7 was charged and discharged at a current density of 50 mA / g in a range of about 2 V to 4.8 V of the half-cell, while charging / discharging was performed, The degree of distribution of F on the surface and the analysis result at this time are shown in Figs. 12 to 15, respectively.

FIG. 12 is an enlarged view of the periphery of MnO in the anode when the anode made of the cathode material according to Example 7 is in a charged state, FIG. 13 is an image showing the center of MnO when the anode made of the cathode material according to Example 7 is in a charged state, (electron energy loss spectroscopy) analysis on the core and the surface.

In Fig. 12, MnO is displayed as a red region and F is displayed as a green region.

Referring to FIG. 12, it can be confirmed that F is mainly distributed on the surface of MnO in the charged state in the anode made of the positive electrode material according to Example 7. Referring to FIG. 13, the peak pattern on the surface of MnO is MnO The peak is shifted to the right with respect to the peak pattern at the center of the MnO, so that it can be confirmed that F forms a chemical bond at the surface of MnO.

FIG. 14 is an enlarged view of the periphery of MnO in the anode when the anode made of the cathode material according to Example 7 is in a discharged state, FIG. 15 is an image showing the center of MnO when the anode made of the cathode material according to Example 7 is in a discharged state, and the EELS analysis results on the core and the surface.

14, MnO is displayed as a red region and F is displayed as a green region in the same manner as in Fig. 12 described above.

Referring to FIG. 15, it can be seen that in the discharge state of the anode made of the positive electrode material according to Example 7, the degree of distribution of F on the surface of MnO is significantly reduced as compared with the above-described charged state. 15, it can be confirmed that the peak pattern on the surface of MnO almost coincides with the peak pattern on the central portion of MnO. Therefore, it can be confirmed that F is separated from the surface of MnO in the discharge state.

In summary, it can be confirmed that the positive electrode made of the positive electrode material according to the manufactured Example 7 can be charged / discharged according to the above-described Reaction Formula 3.

Example  8: LiF -C + FeO  Manufacture of composite anode material

To the LiF-C composite prepared in Preparation Example, FeO powder (Sigma Aldrich, CAS No. 1345-25-1) having an average particle diameter of about 2000 microns was added, and then a planetary ball mill device (Fritsch, Pulverisette 23) And the LiF-C + FeO composite cathode material according to Example 8 was prepared by simple mixing.

Example  9: LiF -C + CoO  Manufacture of composite anode material

CoO powder (Sigma Aldrich, CAS No. 1307-96-6) having an average particle size of about 44 microns was added to the LiF-C composite prepared in Production Example, and then a planetary ball mill device (Fritsch, Pulverisette 23) To prepare a LiF-C + CoO composite cathode material according to Example 9,

Example  10: KF-C + MnO  Manufacture of composite anode material

Except that KF powder (Sigma Aldrich, CAS No. 7789-23-3) was used in place of LiF powder to obtain a KF-C composite.

MnO powder (Sigma Aldrich, CAS No. 1344-43-0) having an average particle size of about 250 microns was added to the obtained KF-C composite, and then mixed using a planetary ball mill (Fritsch, Pulverisette 23) To prepare a KF-C + MnO composite cathode material according to Example 10.

Example  11: NaF -C + MnO  Manufacture of composite anode material

Except that NaF powder (Sigma Aldrich, CAS No. 7681-49-4) was used in place of LiF powder, NaF-C complex was obtained through the same procedure as the above-mentioned production example.

MnO powder (Sigma Aldrich, CAS No. 1344-43-0) having an average particle diameter of about 250 microns was added to the obtained NaF-C composite, and then mixed using a planetary ball mill (Fritsch, Pulverisette 23) To prepare a NaF-C + MnO composite cathode material according to Example 11.

Comparative Example  One: LiF  + C + Mn ₃ O ₄  Preparation of mixture anode material

(Sigma-Aldrich) having a particle size range of from about 1 micron to about 2 microns, a graphite powder (Alfa Aesar) having a particle size range of from about 1 micron to about 20 microns, and a powder of about 6 nm to 20 nm Mn ₃ O ₄ powder having an average particle size was mixed by simple mixing using a planetary ball mill device (Fritsch, Pulverisette 23) at room temperature, and a LiF + C + Mn ₃ O ₄ mixture cathode material according to Comparative Example 1 . The mixture cathode material according to Comparative Example 1 is physically mixed without forming a separate chemical bond between the microscale LiF powder, the graphite powder, and the nano-sized Mn ₃ O ₄ powder.

Comparative Example  2: LiF  + high-energy ball milled C + Mn ₃ O ₄  Preparation of mixture anode material

A graphite powder (Alfa Aesar) having a particle size range of about 1 micron to about 20 microns was charged to a planetary ball mill (Fritsch, Pulverisette 5) and pulverized in an Ar atmosphere at a rate of about 400 rpm for about 48 hours, Energy ball mill to obtain an aggregate of amorphous carbon particles having a particle diameter of about 10 nm to 50 nm. LiF powder (Sigma-Aldrich) having a particle size range of about 1 micron to about 2 microns, and Mn ₃ O ₄ powder having an average particle size of about 6 nm to 20 nm were then mixed with the obtained amorphous carbon particle aggregate, A simple mixture using a ball mill apparatus (Fritsch, Pulverisette 23), a LiF + high-energy ball milled C + Mn ₃ O ₄ mixture according to Comparative Example 2 . The composite anode material according to Comparative Example 2 has a structure in which microscale LiF powder and nano-sized Mn ₃ O ₄ powder are dispersed in a nano-sized amorphous carbon particle aggregate, but a separate chemical bond is formed between the respective constituents They are physically mixed.

Comparative Example  3: LiF  + MnO  Manufacture of composite anode material

LiF powder (Sigma-Aldrich) having a particle size range of about 1 micron to about 2 microns and MnO having an average particle size of about 250 microns The powders were put into a planetary ball mill (Fritsch, Pulverisette 5) and mixed in a high energy ball mill under an Ar atmosphere at a speed of about 500 rpm for about 48 hours without a rest period to obtain LiF + MnO To form a complex. The positive electrode material according to Comparative Example 3 was composed of finely divided LiF particles and MnO The particles are uniformly mixed. In Comparative Example 3, no carbon precursor was added during the high energy ball milling compared to Example 1. [

Rating 1: Example  1 to Example  Evaluation of electrochemical activity of anode made of anode material according to 6

A positive electrode and a half cell were fabricated for the positive electrode material according to Examples 1 to 6 in the same manner as in Measurement Example 3 described above.

Thereafter, a current density of 20 mA / g was applied to the positive electrode made of the positive electrode material of Examples 1 to 6, Comparative Examples 1 and 2 in a range of about 2 V to 4.8 V of the half-cell, The discharge characteristics were measured and are shown in Fig.

Figure 16 is a graph showing the LiF-C + Mn ₃ O ₄ composite electrochemical activity of the anode for a variety of average particle diameter of the Mn ₃ O _4.

Referring to FIG. 16, Mn ₃ O ₄ , which is not generally used as a cathode material, can be used as a cathode for a secondary battery by mixing with LiF-C composite.

In addition, it can be seen that as the average particle diameter of Mn ₃ O ₄ becomes larger, that is, from the first embodiment to the sixth embodiment, the half-cell has gradually smaller specific capacity.

From the above results, it can be seen that the average particle size of the transition metal compound can be variously controlled according to the use of the lithium secondary battery, the kind of the charge carrier ionic compound, and the like, thereby controlling the electrochemical activity of the anode.

Evaluation 2: Example  7 to Example  Evaluation of electrochemical activity of anode made of cathode material according to 9

The positive electrode and the half-cell were fabricated in the same manner as in Evaluation 1 described above with respect to the positive electrode material according to Examples 7 to 9, and then the produced half-cell was subjected to a voltage of 20 mA / g &lt; / RTI &gt; is applied, and the charge / discharge characteristics are measured and shown in Figs. 17 to 19.

17 to 19 are graphs showing the electrochemical activities of the positive electrode made of the positive electrode material according to Examples 7 to 9, respectively.

17 to 19, it can be seen that the anode made of the cathode material according to Examples 7 to 9 exhibits charge / discharge behaviors similar to those of Examples 1 to 6 described above, / g (Example 7), about 320 mAh / g (Example 8), and about 220 mAh / g (Example 9).

From the evaluation 2, it can be confirmed that MnO, FeO, CoO, etc. as well as Mn ₃ O- ₄ as the transition metal element compound can be used as the anode of the secondary battery according to one embodiment.

Rating 3: Example  10, Example  Evaluation of electrochemical activity of anode made of anode material according to 11

The positive electrode and the half-cell were fabricated in the same manner as in Evaluation 1 described above with respect to the positive electrode material according to Example 10 and Example 11, and then the produced half-cell was subjected to a voltage of 50 mA / g, the change of A / A ^{m +} according to the voltage change is measured, and this is shown in FIG. 20 and FIG. 21, respectively.

FIGS. 20 and 21 are graphs showing changes in A / A ^{m +} according to the voltage change of the anode made of the positive electrode material according to Examples 10 and 11. FIG. 20 shows K / K ⁺ / Na ⁺ respectively.

Referring to FIGS. 20 and 21, it can be confirmed that the positive and negative electrodes made according to the tenth and eleventh embodiments exhibit charging / discharging behaviors. On the other hand, the non-capacity measurement results of Example 10 and Example 11 are about 220.1 mAh / g and about 196.6 mAh / g, respectively, showing capacity characteristics usable in a secondary battery.

From the evaluation 3, it can be confirmed that even if a lithium-based compound, a potassium-based compound, a sodium-based compound, or the like is used as a charge carrier ionic compound, it can operate as a positive electrode of a secondary battery according to one embodiment.

Rating 4: Comparative Example  One, Comparative Example  Evaluation of electrochemical activity of anode made of anode material according to 2

A positive electrode and a half cell were fabricated for the positive electrode material according to Comparative Example 1 and Comparative Example 2 in the same manner as in Measurement Example 3 described above.

Then, charge / discharge characteristics obtained when a current density of 50 mA / g was applied to the anode made of the cathode material of Comparative Example 1 and Comparative Example 2 in the range of about 2 V to 4.8 V of the half-cell was measured.

As a result of the measurement, neither of Comparative Example 1 nor Comparative Example 2 exhibited electrochemical activity capable of charging / discharging. This is probably due to the fact that Mn ₃ O _4, which is not suitable as a conventional cathode material, was simply mixed with LiF and carbon particles in Comparative Example 1 and Comparative Example 2.

From the results of Comparative Example 2, it can be seen that when the carbon precursor alone is mixed with Mn ₃ O ₄ or LiF by a high-energy ball milling treatment, it does not exhibit electrochemical activity. From this, it can be confirmed that the electrochemical activity of the above-mentioned reaction formula 3 does not occur when LiF is not made into a nano-sized fine particle through a high energy ball mill.

Rating 5: Comparative Example  Evaluation of electrochemical activity of anode made of cathode material according to 3

For the positive electrode material according to Comparative Example 3, a positive electrode and a half-cell were fabricated in the same manner as in Measurement Example 3 described above. Then, charge / discharge characteristics of the fabricated half-cell were measured under the same conditions as in Evaluation 1 described above, and this is shown in Fig.

22 is a graph showing an electrochemical activity of a positive electrode made of a positive electrode material according to Comparative Example 3. Fig.

Referring to FIG. 22, it can be seen that the capacity characteristics of the positive electrode made of the positive electrode material according to Comparative Example 3 decreased remarkably as the number of times of charging was repeated. That is, even if only LiF is atomized into nano-size, it can be confirmed that the electrochemical activity of Reaction Equation 3 described above does not occur well. This phenomenon is basically attributed to the physical properties of LiF, which has weak conductivity and high electrical insulation.

As a result, it can be seen that stable secondary battery characteristics can be exhibited only in the embodiment in which both LiF and the carbon precursor are microparticulated into nanoscale.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, And falls within the scope of the invention.

10: charge carrier ionic compound-carbon composite
11: Charge carrier ion compound particle
12: Carbon particles
20: transition metal compound

Claims (20)

A charge carrier ionic compound-carbon complex represented by the general formula A _x D _y and containing charge carrier ionic compound particles dispersed on the surface of the carbon particles; And
A transition metal compound physically mixed with said charge carrier ionic compound-carbon composite, said transition metal compound being represented by the general formula M _z R _w ;
Wherein the composite material for a cathode material for a secondary battery includes:
(Wherein A is selected from Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr and Ba; D is F, O, N, Cl, S, P, Br, Se, ), (selected from CO _3), wherein M is Fe, Mn, V, Co, Ni, Cu, Ti, Nb, Mo, Y, Ag, Hf, selected from Ta, wherein R is O, C, S , Cl, Se, I, N , H, (NO 3), (PO 4), (SiO 4), (CO 3), (BO 3), is selected from _{(SO 4 F), 0 <} x≤3 , 0 < y? 2, 0 < z? 4 and 0 & The method of claim 1,
Wherein the charge carrier ionic compound-carbon composite and the transition metal compound have phases distinct from each other. The method of claim 1,
Wherein each of the charge carrier ionic compound particles and each of the carbon particles is a nano-sized particle,
Wherein the charge carrier ionic compound particles are uniformly mixed with the carbon particles in the charge carrier ionic compound-carbon composite. The method of claim 1,
Wherein the charge carrier ionic compound-carbon composite is distributed so as to be adjacent to at least the surface of the transition metal compound. delete The method of claim 1,
Wherein the carbon particles are amorphous carbon particles. The method of claim 1,
Wherein the carbon particles have a particle diameter of 10 nm to 100 nm. The method of claim 1,
Wherein the charge carrier ionic compound particle comprises a first particle having crystallinity and an amorphous second particle. The method of claim 1,
Wherein the charge carrier ionic compound particles have a particle diameter of 5 nm to 100 nm. The method of claim 1,
The charge carriers ionic compound particles, _{LiF, Li 2 O, Li 3} N, LiI, LiCl, Li 2 S, LiOH, Li 2 CO 3, LiBr, Li 3 PO 4, Li 4 P 2 O 7, Li 2 SO 4 , Li ₂ CO ₃ , Li ₄ SiO ₄ , Li ₂ O ₂ , KF, and NaF. The method of claim 1,
Wherein the transition metal compound has crystallinity. The method of claim 1,
The transition metal compound is _{MnO, Mn 2 O 3, Mn} 3 O 4, CoO, Co 3 O 4, FeO, Fe 2 O 3, Fe 3 O 4, V 2 O 5, NiO, Nb 2 O 5, MoO 3 And at least one selected from the group consisting of a positive electrode active material and a negative electrode active material. A method for producing a composite for a secondary battery positive electrode material according to any one of claims 1 to 4 and 6 to 12,
The charge carrier ionic compound precursor and the carbon precursor are mixed by a mechanochemical reaction to form the charge carrier ionic compound-carbon composite,
Wherein the transition metal compound is added to the charge carrier ionic compound-carbon composite. The method of claim 13,
Wherein the mechanochemical reaction is performed using a high-energy ball mill method. The method of claim 13,
Further comprising the step of adding at least one of a binder, a conductive material and a solvent at the time of adding the transition metal compound. The method of claim 13,
And mixing the charge carrier ionic compound-carbon composite and the transition metal compound using physical stirring. Electrolyte;
cathode;
A charge carrier ionic compound-carbon composite comprising carbon particles and charge carrier ionic compound particles represented by the general formula A _x D _y and dispersed on the surface of the carbon particles; and a charge carrier ionic compound- A positive electrode comprising a transition metal compound represented by the general formula M _z R _w ; And
A lithium secondary battery comprising a separator.
(Wherein A is selected from Li, Na, K, Rb, Cs, Be, Mg, Ca, Sr and Ba; D is F, O, N, Cl, S, P, Br, Se, ), (selected from CO _3), wherein M is Fe, Mn, V, Co, Ni, Cu, Ti, Nb, Mo, Y, Ag, Hf, selected from Ta, wherein R is O, C, S , Cl, Se, I, N , H, (NO 3), (PO 4), (SiO 4), (CO 3), (BO 3), is selected from _{(SO 4 F), 0 <} x≤3 , 0 < y? 2, 0 < z? 4 and 0 & The method of claim 17,
Wherein the positive electrode is subjected to oxidation and reduction of charge carrier ions on the surface of the transition metal compound. The method of claim 17,
In the charged state of the lithium secondary battery,
Wherein the charge carrier ionic compound is separated into a charge carrier ion and an anion, and the anion is chemically bonded to the transition metal compound. delete

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