JP2004014340A - Electrode material, lithium ion battery using it and manufacturing method of electrode material - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrode material capable of obtaining a high discharge capacity, stable charge-discharge cycle performance, a high filling property, a high output and the like by using an inexpensive element abundant as a resource, to provide a lithium ion battery using it and to provide a manufacturing method of the electrode material. <P>SOLUTION: This electrode material is characterized by forming each secondary particle 3 by collecting a plurality of primary particles 1 expressed by a formula Li<SB>x</SB>A<SB>y</SB>B<SB>z</SB>O<SB>4</SB>(wherein A is at least one kind selected from Cr, Mn, Fe, Co, Ni and Cu; B is at least one kind selected from Mg, Ca, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, Sc, Y and a rare-earth elements; 0≤x<2; 0<y<1.5; and 0≤z<1.5), and by interlaying three-dimensional mesh-like electron conducting substances 2 among the plurality of primary particles 1, 1. <P>COPYRIGHT: (C)2004,JPO

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to an electrode material, a secondary battery using the same, and a method for producing the electrode material, and particularly, an electrode material suitable for a battery electrode material, and further a positive electrode material for a lithium ion battery, and an electrode material suitable for the same. The present invention relates to a method for producing a lithium ion battery and an electrode material.
[0002]
[Prior art]
2. Description of the Related Art In recent years, nonaqueous electrolyte secondary batteries such as lithium ion batteries have been proposed and put to practical use as batteries expected to be reduced in size, weight, and capacity.
This lithium ion battery is made of lithium cobalt oxide (LiCoO ₂ ), Lithium nickelate (LiNiO) ₂ ), Lithium manganate (LiMn) ₂ O ₄ ) Is used as a positive electrode material, and has an excellent feature that the electromotive force exceeds 4 V despite its small size.
On the other hand, as a positive electrode material for a lithium ion battery, Fe, which is abundant in resources and inexpensive, has attracted attention. For example, LiFePO ₄ Since the phosphoric acid compound represented by has a potential of about 3.3 V with respect to metal Li, it can be used as a chargeable and dischargeable positive electrode material.
[0003]
[Problems to be solved by the invention]
However, the conventional lithium ion battery has various problems in the cathode material used.
For example, LiCoO ₂ It is pointed out that, in addition to the problem that the reserve amount of Co is small and expensive, there are also problems such as toxicity of Co.
Also, LiNiO ₂ Although they have excellent charge / discharge characteristics, they are not inexpensive, and have many problems such as stability at high temperatures and rapid deterioration of characteristics due to composition deviation from a stoichiometric ratio.
LiMn ₂ O ₄ Is a problem that Mn is eluted at a high temperature, ³⁺ The problem of cycle deterioration due to the Jahn-Teller distortion is pointed out.
[0004]
On the other hand, LiFePO ₄ Has the advantage that there is no problem of toxicity to the human body and the environment, but LiCoO ₂ And the like, are still insufficient in terms of electromotive force and high capacity.
As described above, the conventional various positive electrode materials have various problems as described above, and also have a common problem that the current density that can be passed at the time of charging and discharging the battery is low, so that it is difficult to increase the output. It is one of the factors that hinders practical application.
[0005]
The present invention has been made to solve the above-described problems, and realizes high discharge capacity, stable charge / discharge cycle performance, high filling property, high output, and the like by using inexpensive and resource-rich elements. It is an object of the present invention to provide an electrode material that can be used, a lithium ion battery using the same, and a method for manufacturing the electrode material.
[0006]
[Means for Solving the Problems]
In order to solve the above problems, the present inventors have conducted intensive studies and as a result, it has been found that the lithium compound used as a positive electrode material has a low electronic conductivity, a low current density that can flow during charging and discharging, and a high output. Considering that this is one of the causes of difficulty, in order to increase the electronic conductivity of the lithium compound used as the positive electrode material, a plurality of primary particles made of the lithium compound are aggregated to form secondary particles, and It has been found that a composite positive electrode material having excellent electronic conductivity can be obtained by interposing an electronic conductive substance such as carbon between the primary particles.
[0007]
To further explain this technical idea, LiCoO ₂ , LiNiO ₂ , LiMn ₂ O ₄ , LiFe _1-x M _x PO ₄ (Where M is Co, Mn, Ni) when a lithium compound such as Li is used for the positive electrode material of the lithium ion battery, the lithium is charged from the positive electrode material by charging the battery. ⁺ Is desorbed, and conversely, during discharge, Li ⁺ Is added. This Li ⁺ Desorption and addition occur from the surface of the particles, but at the same time, reduction and oxidation of transition metal ions such as Co, Ni, Mn, and Fe occur in the electrode material.
[0008]
That is, at the reaction point on the surface of the positive electrode material, Li ⁺ In the conventional lithium-ion battery, the electronic conductivity of the material itself is low, and the inability to keep up with the supply of electrons is one of the factors that hinders high output. Therefore, if the ability to supply electrons can be increased by including a substance having electron conductivity in the material, it is possible to increase the output of the battery.
In particular, LiFe _1-x M _x PO ₄ In the case of a system material, since the electronic conductivity of the material itself is low, the effect of the present invention is extremely high.
[0009]
Next, characteristics of the electrode material of the present invention, a lithium ion battery using the same, and a method of manufacturing the electrode material will be described.
That is, the electrode material of the present invention has the formula Li _x A _y B _z PO ₄ (However, A is at least one selected from Cr, Mn, Fe, Co, Ni, Cu, B is Mg, Ca, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, Secondary particles obtained by assembling a plurality of primary particles consisting of at least one selected from Sc, Y and rare earth elements, 0 ≦ x <2, 0 <y <1.5, 0 ≦ z <1.5) And an electronic conductive substance interposed between the primary particles.
[0010]
Preferably, the electronic conductive material is carbon.
The content of the electron conductive material in the secondary particles is preferably 0.1 to 30% by weight.
[0011]
A lithium ion battery according to the present invention includes a positive electrode using the electrode material according to the present invention.
[0012]
The production method of the electrode material of the present invention is represented by the formula Li _x A _y B _z PO ₄ (However, A is at least one selected from Cr, Mn, Fe, Co, Ni, Cu, B is Mg, Ca, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, A plurality of primary particles made of a material represented by at least one selected from Sc, Y and rare earth elements and represented by 0 ≦ x <2, 0 <y <1.5, 0 ≦ z <1.5) are collected. A method for producing an electrode material in which secondary particles are used as secondary particles and an electronic conductive substance is interposed between these primary particles, wherein Li, A (where A is Cr, Mn, Fe, Co, Ni , Cu, at least one selected from the group consisting of Mg, Ca, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, Sc, Y, and a rare earth element. ), P, an electron conductive substance or a precursor of the electron conductive substance. No solution or suspension is sprayed, characterized by heating.
[0013]
It is preferable that the electron conductive substance is carbon alone.
The precursor of the electronic conductive substance is preferably an organic compound.
[0014]
BEST MODE FOR CARRYING OUT THE INVENTION
An embodiment of the electrode material of the present invention, a lithium ion battery using the same, and a method for manufacturing the electrode material will be described.
The electrode material of the present embodiment has the formula Li _x A _y B _z PO ₄ (However, A is at least one selected from Cr, Mn, Fe, Co, Ni, Cu, B is Mg, Ca, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, Secondary particles obtained by assembling a plurality of primary particles consisting of at least one selected from Sc, Y and rare earth elements, 0 ≦ x <2, 0 <y <1.5, 0 ≦ z <1.5) And an electronic conductive substance is interposed between the primary particles.
[0015]
This electrode material is preferably a secondary particle formed by assembling a plurality of primary particles coated with an electronic conductive substance, and is preferably exposed to the outside of the primary particles constituting the secondary particles. It is also preferable that the portion where the electrode is present is covered with an electronic conductive material. Further, it is preferable that the primary particles are joined via an electronic conductive substance.
Here, the term “joined” means that the primary particles are not merely secondary particles in a state of an aggregate, but at least one secondary particle is formed when forming an electrode using the present material. It means that they are tightly bound to the extent that they behave as particles. In the secondary particles, it is preferable that the electron conductive substance has a three-dimensional network shape.
[0016]
FIG. 1 is a cross-sectional view showing an example of the electrode material of the present embodiment, in which a plurality of primary particles 1 represented by the above formulas are aggregated, and these primary particles 1, 1,. And the secondary particles 3 having a spherical or polygonal shape as a whole.
[0017]
For A, Mn, Fe, Co, and Ni are preferable, and for B, Mg, Ca, Sr, Ti, Zn, and Al are preferable in terms of high discharge potential, abundant resource amount, safety, and the like.
Here, examples of the rare earth element include La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, and Lu.
As the electron conductive material, carbon is most preferable in terms of chemical stability, safety and cost, but other than carbon, metal is preferable, and particularly, Au, Pt, Ag, Pd, Ru, Rh, Ir, etc. Is preferred. Among these, Ag is preferred.
[0018]
Here, the average particle size of the primary particles is preferably from 0.001 to 20 μm, and more preferably from 0.05 to 2 μm.
The reason for this is that if the average particle size is smaller than 0.001 μm, the crystal structure may be destroyed due to volume change due to charge and discharge. This is because the supply amount of uranium is insufficient, and the utilization efficiency is reduced.
[0019]
The thickness of the electron conductive material layer 2 is preferably 0.001 to 1 μm, and more preferably 0.01 to 0.2 μm.
The reason is that if the thickness is less than 0.001 μm, the electron conductivity is insufficient and the supply amount of electrons is insufficient, and if the thickness is more than 1 μm, the ratio of the active material in the electrode material is reduced. This is because the active material is not effectively used.
[0020]
Further, the average particle size of the secondary particles is preferably from 0.01 to 200 μm, and more preferably from 0.1 to 50 μm.
The reason is that if the average particle size is smaller than 0.01 μm, a large amount of binder is required when preparing the electrode material mixture, and as a result, the ratio of the active material in the electrode material mixture decreases, This is because the conductivity of the electrode material mixture also decreases, and if the average particle diameter is larger than 200 μm, voids are easily generated in the electrode material mixture.
[0021]
The shape of the secondary particles is preferably spherical. This is because the close-packing is easy, so that the filling amount of the positive electrode material per unit volume increases, and the battery volume can be reduced even with the same capacity.
Further, the content of the electronic conductive substance contained in one secondary particle is preferably 0.1 to 30% by weight, more preferably 1 to 20% by weight. If the content of the electronic conductive material is less than 0.1% by weight, the electronic conductivity may not be sufficiently exhibited. If the content is more than 30% by weight, the electronic conductive material may be more than the amount required to obtain the required conductivity. Is contained, and the weight and the volume density of the positive electrode active material in the particles are reduced.
[0022]
The electron conductive substance contained in the secondary particles does not form a compound with other components. Also, this electronically conductive material has the formula Li _x A _y B _z PO ₄ (However, A is at least one selected from Cr, Mn, Fe, Co, Ni, Cu, B is Mg, Ca, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, Sc, Y, at least one selected from rare earth elements, present outside the primary particles represented by 0 ≦ x <2, 0 <y <1.5, 0 ≦ z <1.5) It is significantly different from a simple mixture of the primary particles of the above formula and an electronic conductive substance.
It is preferable that the electron conductive substance is uniformly present in the secondary particles, and is preferably present in a network between the primary particles.
[0023]
If this electrode material is used as a positive electrode material of a lithium ion battery, the obtained lithium ion battery has high discharge capacity, stable charge / discharge cycle performance, high filling property, high output, and the like.
[0024]
The manufacturing method of the electrode material according to the present embodiment includes Li, A (where A is at least one selected from Cr, Mn, Fe, Co, Ni and Cu), and B (where B is Mg and Ca). , Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, Sc, Y, at least one element selected from rare earth elements), P, and an electronic conductive material or an electronic conductive material. The solution or suspension containing the precursor is sprayed and heated.
[0025]
Examples of Li include LiCl, LiCH ₃ Li salts such as COO and LiOH can be used. Further, as Fe, for example, FeCl ₂ , FeBr ₂ , Fe (CH ₃ COO) ₂ And the like can be used. Further, as Mn, Co, Ni, etc., for example, MnCl ₂ , Mn (CH ₃ COO) ₂ , NiCl ₂ And the like. As Al, for example, AlCl ₃ And the like. As P, for example, H ₃ PO ₄ , NH ₄ H ₂ PO ₄ , (NH ₄ ) ₂ HPO ₄ Etc. can be used.
In particular, in order to obtain a uniform mixed raw material that does not cause reaction and aggregation before spraying, each metal component is chloride, and P is H ₃ PO ₄ It is preferable to use
[0026]
As the electron conductive material, besides carbon, metals, particularly noble metals such as Au, Pt, Ag, Pd, Ru, Rh, and Ir are preferably used. Among them, Ag is preferable.
Here, the precursor of the electron conductive substance is a substance that becomes an electron conductive substance by heating, and the precursor of the electron conductive substance includes, in addition to an organic compound, a metal salt, a metal alkoxide, and a metal. And the like are preferably used.
[0027]
As the above-mentioned carbon, simple carbon or a carbon compound is used.
As the simple carbon, for example, carbon black, acetylene black, graphite and the like can be used, and any of carbon black and acetylene black is preferable. The primary particle diameter of these carbon particles is preferably from 1 to 1000 nm, more preferably from 10 to 200 nm.
[0028]
These materials are dissolved or dispersed in a solvent to form a uniform solution or suspension, and the solution or suspension is sprayed and heated under an inert atmosphere or a reducing atmosphere. As the solvent, for example, water, alcohols, ketones, and the like can be used, but water is preferable in terms of ease of use and safety.
The concentration of the raw material components in this solution or suspension is not particularly limited as long as it can be sprayed, but is preferably 1 to 30% by weight in order to obtain a good spray state.
[0029]
The particle size of the droplets at the time of spraying is preferably 0.05 to 500 μm. The heating temperature at the time of spraying varies depending on the raw material used, but is preferably 500 to 1000C, more preferably 650 to 900C. This is because if the heating temperature is lower than 500 ° C., decomposition / reaction does not proceed sufficiently, the crystallinity is lowered, and there is a possibility of becoming amorphous. If it is higher, the product may be melted and vitrified.
As an atmosphere for spraying and heating, especially when A is Fe, N ₂ , Ar or the like is preferable. ₂ A reducing atmosphere containing a reducing gas such as
[0030]
In the production method of the present embodiment, the raw material of each component is sprayed as fine droplets in a state of being uniformly dispersed in a solution or suspension and heated in that state, so that the thermal decomposition reaction is instantaneous. Occurs and the formula Li _x A _y B _z PO ₄ (However, A is at least one selected from Cr, Mn, Fe, Co, Ni, Cu, B is Mg, Ca, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, At least one selected from the group consisting of Sc, Y, and rare-earth elements, and electronic conductivity between primary particles made of a material represented by 0 ≦ x <2, 0 <y <1.5, and 0 ≦ z <1.5) Secondary particles formed by interposing a substance are formed.
[0031]
At this time, since the electron conductive substance or the precursor of the electron conductive substance, which has been uniformly dispersed in the solution or suspension, is also uniformly dispersed in the droplet, the secondary particles may be generated. Then, the particles are taken in a state where they are uniformly present in the secondary particles, and secondary particles having an electron conductive substance interposed between the primary particles are obtained. Further, the primary particles are joined to each other via the electronic conductive material, the individual primary particles are coated with the electronic conductive material, and the outside of the secondary particles is also coated with the electronic conductive material.
In addition, the incorporated electronic conductive substance or the precursor of the electronic conductive substance attracts each other, and the precursor of the electronic conductive substance changes into an electronic conductive substance when heated, so that the electronic conductive substance is contained in the secondary particles. In the form of a network.
[0032]
In this case, each raw material component is uniformly dispersed and mixed in the solvent, and if a good spray state is obtained, each component may not be dissolved in the solvent. Is more preferably soluble in a solvent.
In addition, as long as the electronic conductive substance or the precursor of the electronic conductive substance is also soluble in the solvent, each component is uniformly mixed at the molecular level by dissolving in the solvent, so that there is no deviation or variation in composition. Particulate matter is obtained and is preferred.
[0033]
When carbon alone is used as the electron conductive substance, for example, carbon black, acetylene black, graphite, or the like can be used. In particular, any one of carbon black and acetylene black is preferable.
[0034]
In the case where a carbon compound is used as a precursor of the electron conductive substance, an organic compound can be used. The organic compound is not particularly limited as long as it does not volatilize during heating. For example, polyethylene glycol, polypropylene glycol, polyethylene imine, polyvinyl alcohol, polyacrylic acid (salt), polyvinyl butyral, polyvinyl pyrrolidone, or a copolymer thereof is preferably used.
Further, for example, sugars such as sugar alcohols, sugar esters, and cellulose, or polyglycerin, polyglycerin esters, sorbitan esters, polyoxyethylene sorbitan, and various water-soluble organic surfactants can be used.
Further, if a phosphoric acid ester, a phosphoric acid ester salt, or the like is used, it can be used as a phosphorus component simultaneously with a carbon component.
[0035]
When a carbon component is used as the electron conductive material and an organic compound is used as a precursor thereof, when an organic compound that is soluble in a solvent is used, not only the other components but also the carbon component is dissolved in the solution. Since the particles are uniformly dispersed and mixed at the level, when the secondary particles are generated, the carbon particles are more uniformly present in the secondary particles, and a better network structure is formed. Therefore, the organic compound is preferably a compound soluble in a solvent, and particularly preferably a water-soluble organic compound when the solvent is water.
[0036]
According to the electrode material of the present embodiment, the formula Li _x A _y B _z PO ₄ (However, A is at least one selected from Cr, Mn, Fe, Co, Ni, Cu, B is Mg, Ca, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, Secondary particles obtained by assembling a plurality of primary particles consisting of at least one selected from Sc, Y and rare earth elements, 0 ≦ x <2, 0 <y <1.5, 0 ≦ z <1.5) In addition, since an electronic conductive substance is interposed between the primary particles, high discharge capacity, stable charge / discharge cycle performance, high filling property, high output, and the like can be realized.
In addition, since the elements to be used are inexpensive and abundant in resources, an inexpensive lithium ion battery can be provided.
[0037]
According to the lithium ion battery of the present embodiment, since the positive electrode is formed using the electrode material of the present embodiment, a lithium ion battery having high discharge capacity, stable charge / discharge cycle performance, high filling property, high output, and the like is provided. can do.
[0038]
According to the electrode material manufacturing method of the present embodiment, Li, A (where A is at least one selected from Cr, Mn, Fe, Co, Ni, and Cu), and B (where B is Mg , Ca, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, Sc, Y, at least one element selected from the group consisting of rare earth elements), P, and an electron conductive material or electron conductivity. Since the solution or suspension containing the precursor of the substance is sprayed and heated, the reaction can be performed in the form of fine droplets, and secondary particles having a particle size of 0.01 to 50 μm are generated. In addition, spherical particles can be formed.
[0039]
In addition, by joining primary particles having an average particle diameter of 0.001 to 20 μm with an electronic conductive substance having a thickness of 1 to 1000 nm, an electronic conductive substance exists in a network between a plurality of primary particles. Secondary particles can be easily produced.
[0040]
【Example】
Hereinafter, the present invention will be described specifically with reference to Examples and Comparative Examples, but the present invention is not limited to these Examples.
For example, in this example, metal Li was used for the negative electrode in order to reflect the behavior of the electrode material itself in the data. ₄ Ti ₅ O ₁₂ And the like. Further, a solid electrolyte may be used instead of the electrolytic solution and the separator.
[0041]
(Example 1)
LiCl, FeCl ₂ And H ₃ PO ₄ Was dissolved in pure water so that the ratio of these substances was 1: 1: 1 and the concentration was 0.1 mol / kg, to obtain an aqueous solution A.
Next, 1000 g of this aqueous solution A and 2.4 g of acetylene black were mixed, and thereafter, the mixture was stirred with a stirrer for 2 hours to uniformly disperse acetylene black. Next, this dispersion was atomized using an ultrasonic atomizer, ₂ The gas was introduced as a carrier gas into a heat treatment furnace at 700 ° C. to perform thermal decomposition. Thereafter, the pyrolyzate was recovered to obtain a spherical electrode material powder (A: secondary particles) having a particle size of 0.2 to 5 μm.
LiFePO of this electrode material powder (A) ₄ The / C ratio was 80/12 by weight.
[0042]
(Example 2)
1000 g of the aqueous solution A of Example 1 and 5.7 g of sucrose were mixed to obtain a uniform aqueous solution B. Next, the aqueous solution B was atomized using an ultrasonic atomizer, ₂ The gas was introduced as a carrier gas into a heat treatment furnace at 700 ° C. to perform thermal decomposition. Thereafter, the pyrolysis product was recovered to obtain a spherical electrode material powder (B: secondary particles) having a particle size of 0.2 to 5 μm.
Here, sucrose (C ₁₂ H ₂₂ O ₁₁ ) Is regarded as 12C, this electrode material powder (B) LiFePO ₄ The / C ratio was 80/12 by weight.
[0043]
(Comparative example)
An electrode material powder (C) was obtained in the same manner as in Example 1 except that carbon or sucrose as a carbon source was not added to the raw material solution.
[0044]
(Production of lithium ion battery)
92 mg of the obtained powder (A) and 8 mg of polytetrafluoroethylene (PTFE) as a binder were kneaded and rolled to obtain an electrode material mixture film (A). Similarly, 92 mg of the obtained powder (B) and 8 mg of polytetrafluoroethylene (PTFE) as a binder were kneaded and rolled to obtain an electrode material mixture film (B).
Further, 80 mg of the obtained powder (C), 12 mg of acetylene black as a conductive additive, and 8 mg of polytetrafluoroethylene (PTFE) as a binder were kneaded and rolled to obtain an electrode material mixture film (C).
[0045]
After pressing these films (A) to (C) on a stainless steel mesh current collector, the area is 2 cm. ² And the positive electrodes of Examples 1, 2 and Comparative Example were punched out.
After vacuum drying the obtained positive electrode, batteries of Examples 1 and 2 and Comparative Example were produced using an HS standard cell (manufactured by Hosen Co., Ltd.) under a dry Ar atmosphere.
Metal Li for negative electrode, porous polypropylene membrane for separator, 1M LiPF for electrolyte ₆ A solution (solvent: ethylene carbonate / diethyl carbonate = 1/1) was used.
[0046]
(Battery charge / discharge test)
A battery charge / discharge test was performed on the batteries of Examples 1 and 2 and the comparative example.
In the charge / discharge test, cutoff voltage: 3 to 4 V, current density: 0.5 mAcm ^-2 At a constant current of room temperature.
FIG. 2 shows the initial charge / discharge characteristics, and FIG. 3 shows the results of the charge / discharge cycle test. According to the result of the battery charge / discharge test, the current density was 0.5 mAcm ^-2 At a high output of about 150 mAhg ^-1 High initial capacity and excellent cycle characteristics.
[0047]
【The invention's effect】
According to the electrode material of the present invention, the formula Li _x A _y B _z PO ₄ (However, A is at least one selected from Cr, Mn, Fe, Co, Ni, Cu, B is Mg, Ca, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, Secondary particles obtained by assembling a plurality of primary particles consisting of at least one selected from Sc, Y and rare earth elements, 0 ≦ x <2, 0 <y <1.5, 0 ≦ z <1.5) In addition, since an electronic conductive substance is interposed between the primary particles, high discharge capacity, stable charge / discharge cycle performance, high filling property, high output, and the like can be realized.
In addition, since the elements to be used are inexpensive and abundant in resources, an inexpensive lithium ion battery can be provided.
[0048]
According to the lithium ion battery of the present invention, since a positive electrode using the electrode material of the present invention is provided, a lithium ion battery having high discharge capacity, stable charge / discharge cycle performance, high filling properties, high output, and the like is provided. can do.
[0049]
According to the method for manufacturing an electrode material of the present invention, Li, A (where A is at least one selected from Cr, Mn, Fe, Co, Ni, and Cu), and B (where B is Mg, Ca, Sr, Ba, Ti, Zn, B, Al, Ga, In, Si, Ge, Sc, Y, at least one element selected from rare earth elements), P, and an electronic conductive substance or an electronic conductive substance The solution or suspension containing the precursor is sprayed and heated, so that the reaction can be performed in the form of fine droplets, and secondary particles having an average particle size of 0.01 to 200 μm are generated. In addition, spherical particles can be formed.
In addition, by joining the primary particles with the electronic conductive material, secondary particles in which the electronic conductive material exists in a network between a plurality of primary particles can be easily produced.
[Brief description of the drawings]
FIG. 1 is a cross-sectional view illustrating an example of an electrode material according to an embodiment of the present invention.
FIG. 2 is a diagram showing initial charge / discharge characteristics of Examples 1 and 2 of the present invention and a comparative example.
FIG. 3 is a diagram showing the results of a charge / discharge cycle test of Examples 1 and 2 of the present invention and a comparative example.
[Explanation of symbols]
1 Primary particles
2 Electronic conductive material layer
3 Secondary particles

Claims (7)

Formula Li _x A _y B _z PO ₄ (where A is at least one selected from Cr, Mn, Fe, Co, Ni, Cu, and B is Mg, Ca, Sr, Ba, Ti, Zn, B, Al , Ga, In, Si, Ge, Sc, Y, at least one selected from rare earth elements, 0 ≦ x <2, 0 <y <1.5, 0 ≦ z <1.5) Characterized in that a plurality of are aggregated to form secondary particles, and an electronic conductive substance is interposed between the primary particles. The electrode material according to claim 1, wherein the electronic conductive substance is carbon. 3. The electrode material according to claim 1, wherein the content of the electron conductive substance in the secondary particles is 0.1 to 30% by weight. 4. A lithium-ion battery comprising a positive electrode using the electrode material according to claim 1. Formula Li _x A _y B _z PO ₄ (where A is at least one selected from Cr, Mn, Fe, Co, Ni, Cu, and B is Mg, Ca, Sr, Ba, Ti, Zn, B, Al , Ga, In, Si, Ge, Sc, Y, at least one selected from rare earth elements, 0 ≦ x <2, 0 <y <1.5, 0 ≦ z <1.5) A method of producing an electrode material comprising:
Li, A (where A is at least one selected from Cr, Mn, Fe, Co, Ni and Cu), and B (where B is Mg, Ca, Sr, Ba, Ti, Zn, B, A solution or suspension containing at least one selected from the group consisting of Al, Ga, In, Si, Ge, Sc, Y, and a rare earth element), P, and an electronic conductive substance or a precursor of the electronic conductive substance. A method for producing an electrode material, which comprises spraying and heating. The method for manufacturing an electrode material according to claim 5, wherein the electron conductive substance is carbon alone. The method according to claim 5, wherein the precursor of the electronic conductive substance is an organic compound.

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