KR101656076B1 - Electrode Material Improved Energy Density and Lithium Secondary Battery Comprising the Same - Google Patents

Abstract

The present invention is characterized by comprising at least one lithium metal oxide particle selected from the group consisting of a compound represented by the following formula (1) and a compound represented by the following formula (2), and lithium metal phosphate particles represented by the following formula (3) Thereby providing an electrode active material.


Li _x M _y Mn _{2 - y} O _{4 - z z} (1)
In this formula,
0.9? X? 1.2, 0 <y <2, 0? Z <0.2;
M is at least one element selected from the group consisting of Al, Mg, Ni, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, ;
A is one or more of an anion of -1 or -2.


(1-x) LiM'O _2-y A _y -xLi ₂ MnO _{3 -y '} A _y' (2)
In this formula,
M 'is Mn _a M _b ;
M is one or more selected from the group consisting of Ni, Ti, Co, Al, Cu, Fe, Mg, B, Cr, Zr, Zn and two period transition metals;
A is at least one selected from the group consisting of PO ₄ , BO ₃ , CO ₃ , F and NO ₃ anions,
0 < x &lt;1; 0 &lt; y? 0.02; 0 &lt; y ' 0.5? A? 1.0; 0? B? 0.5; a + b = 1.


Li1 ₊ aFe1 _-xM &quot; _x (PO4 _-b ) _Xb (3)
In this formula,
M &quot; is at least one selected from Al, Mg and Ti,
X is at least one selected from F, S and N,
-0.5? A? + 0.5, 0? X? 0.5, and 0? B?

Description

TECHNICAL FIELD [0001] The present invention relates to an electrode active material having improved energy density and a lithium secondary battery including the electrode active material.

The present invention relates to an electrode active material having improved energy density and a lithium secondary battery including the electrode active material.

As technology development and demand for mobile devices are increasing, the demand for secondary batteries as energy sources is rapidly increasing. Among such secondary batteries, lithium secondary batteries having high energy density and voltage, long cycle life and low self- It has been commercialized and widely used.

Such a lithium secondary battery has mainly lithium-containing cobalt oxide (LiCoO ₂₎ is used, and that in addition to the layered crystal structure of LiMnO _2, lithium-containing manganese oxide, lithium-containing nickel oxides such as LiMn ₂ O ₄ of spinel crystal structure (LiNiO ₂ ) is also considered.

LiCoO ₂ has excellent properties such as excellent cycle characteristics and is widely used at present, but its safety is low and it is expensive due to the resource limit of cobalt as a raw material, and there is a limit to mass use as a power source for fields such as electric vehicles. LiNiO ₂ is difficult to apply to actual mass production process at a reasonable cost due to its characteristics depending on its manufacturing method.

On the other hand, lithium manganese oxides such as LiMnO ₂ and LiMn ₂ O ₄ have the advantage of using manganese which is rich in resources and environment-friendly as a raw material, and thus attracts much attention as a cathode active material capable of replacing LiCoO ₂ . However, these lithium manganese oxides also have a disadvantage of poor cycle characteristics and the like.

First, LiMnO ₂ has a disadvantage in that the initial capacity is small, and in particular, several tens of charge / discharge cycles are required until a certain capacity is reached. In addition, LiMn ₂ O ₄ has a disadvantage in that the capacity deteriorates as the cycle continues, and in particular, at a high temperature of 50 ° C or higher, the cycle characteristics are drastically lowered due to decomposition of the electrolytic solution and elution of manganese.

On the other hand, among the lithium-containing manganese oxides, there are Li ₂ MnO _{3 in} addition to LiMnO ₂ and LiMn ₂ O ₄ . Li ₂ MnO ₃ has excellent structural stability but is not electrochemically inert and thus can not be used as a cathode active material of a secondary battery. Therefore, among some prior arts, there is proposed a technique of using Li ₂ MnO ₃ as a cathode active material by forming a solid solution with LiMO ₂ (M = Co, Ni, Ni _0.5 Mn _0.5 , Mn). Such a solid solution cathode active material has a high possibility of decomposition of electrolyte and gas generation at a high voltage, and the LiMO ₂ (M = Co, Ni, Ni _0.5 Mn &lt; / RTI &gt; _0.5 , Mn).

Further, due to the crystal structure of the lithium-containing manganese oxide, it is difficult to increase the output at a low temperature and to expect an improvement in the energy density.

Therefore, a need exists for a technique capable of solving such a problem.

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

An object of the present invention is to provide an electrode active material having an effect of improving a low temperature output and an energy density and a lithium secondary battery including the electrode active material.

Accordingly, in a non-limiting example of the present invention, the electrode active material is a lithium metal oxide particle comprising at least one lithium metal oxide particle selected from a compound represented by the following formula (1) and a compound represented by the following formula (2) And lithium metal phosphide particles.

Li _x M _y Mn _{2 - y} O _{4 - z z} (1)

In this formula,

0.9? X? 1.2, 0 <y <2, 0? Z <0.2;

M is at least one element selected from the group consisting of Al, Mg, Ni, Co, Fe, Cr, V, Ti, Cu, B, Ca, Zn, Zr, Nb, Mo, Sr, Sb, W, ;

A is one or more of an anion of -1 or -2.

(1-x) LiM'O _2-y A _y -xLi ₂ MnO _{3 -y '} A _y' (2)

In this formula,

M 'is Mn _a M _b ;

M is one or more selected from the group consisting of Ni, Ti, Co, Al, Cu, Fe, Mg, B, Cr, Zr, Zn and two period transition metals;

A is at least one selected from the group consisting of PO ₄ , BO ₃ , CO ₃ , F and NO ₃ anions,

0 &lt; x &lt;1; 0 < y? 0.02; 0 < y &apos; 0.5? A? 1.0; 0? B? 0.5; a + b = 1.

Li1 ₊ aFe1 _-xM &quot; _x (PO4 _-b ) _Xb (3)

In this formula,

M &quot; is at least one selected from Al, Mg and Ti,

X is at least one selected from F, S and N,

-0.5? A? + 0.5, 0? X? 0.5, and 0? B?

The compound represented by the formula (1) may have an average particle diameter (D50) in a range of 3 mu m or more to 20 mu m or less.

The compound represented by the formula (2) may have an average particle diameter (D50) within a range of 1 탆 or more and 15 탆 or less.

The compound represented by the formula (3) may have an average particle diameter (D50) within a range of 100 nm or more to 2 占 퐉 or less.

Lithium metal phosphide particles (LFP) represented by the chemical formula (3) is a material having low electrical conductivity. The size of the lithium metal phosphate particles (LFP) must be reduced to the nanometer level to secure the electrical conductivity. Increase.

However, in general, when the average particle size of the active material is too small, a problem occurs in the production process and the surface area becomes relatively wide, so that the use of the same amount of binder causes a problem that the adhesive force is reduced. In addition, when the average particle size of the active material is too large, the electric conductivity deteriorates and the output characteristics are deteriorated.

The compound represented by the formula (1) may have a spherical shape.

The compound represented by the formula (2) may have a spherical shape.

The compound represented by the formula (3) may have a spherical shape.

The mixing ratio of the lithium metal oxide particles to the lithium metal phosphate may be in the range of 3: 7 to 9: 1 by weight.

The electrode active material may further include a conductive coating layer present on the surface of the lithium metal oxide.

The conductive coating layer may include at least one conductive particle.

The conductive coating layer may have a thickness within a range from 0.1 nm or more to 2 占 퐉 or less.

If the thickness of the conductive coating layer is excessively large, it may cause a problem that the output characteristics are degraded by acting as a resistor, which is not preferable.

The electrode active material may further include a conductive coating layer present on the surface of the lithium metal phosphate.

The conductive coating layer may include at least one conductive particle.

The conductive coating layer may have a thickness within a range of 10 nm or more and 500 nm or less.

The conductive coating layer may include a conductive carbon black.

The conductive carbon black may be at least one selected from the group consisting of acetylene black, ketjen black, furnace black, oil-furnace black, Columbia carbon, channel black, lamp black,

The lithium metal oxide may be secondary particles composed of primary particles, and the secondary particles may have a porosity of 10% or more to 50% or less.

The lithium metal phosphate may be secondary particles composed of primary particles, and the secondary particles may have a porosity of 10% or more to 50% or less.

When the pore size is too low, the active material particles may be broken when the current collector is rolled, resulting in a problem of deteriorated cycle characteristics. On the contrary, when the pore size is excessively high, the overall battery cell thickness becomes thick, And the output characteristic may be lowered.

The present invention also provides a lithium secondary battery comprising the electrode active material as a cathode active material.

The lithium secondary battery may include a carbon-based material and / or Si as a negative electrode active material.

The lithium secondary battery may be one selected from the group consisting of a lithium ion battery, a lithium ion polymer battery, and a lithium polymer battery.

Generally, the positive electrode is prepared by applying an electrode mixture, which is a mixture of a positive electrode active material, a conductive material and a binder, on a positive electrode collector, followed by drying. If necessary, a filler may be further added to the mixture.

The cathode active material may be a layered compound such as lithium cobalt oxide (LiCoO ₂ ) or lithium nickel oxide (LiNiO ₂ ), or a compound substituted with one or more transition metals, in addition to the electrode active material represented by the general formulas (1), ( ₂ ) and ( ₃ ). Lithium manganese oxides such as Li _{1 + x} Mn _{2 -x} O ₄ (where x is 0 to 0.33), LiMnO ₃ , LiMn ₂ O ₃ , LiMnO ₂ and the like; Lithium copper oxide (Li ₂ CuO ₂ ); Vanadium oxides such as LiV ₃ O ₈ , LiFe ₃ O ₄ , V ₂ O ₅ and Cu ₂ V ₂ O ₇ ; A Ni-site type lithium nickel oxide expressed by the formula LiNi _1-x M _x O ₂ (where M = Co, Mn, Al, Cu, Fe, Mg, B or Ga and x = 0.01 to 0.3); Formula _{LiMn 2-x M x O 2} ( where, M = Co, Ni, Fe , Cr, and Zn, or Ta, x = 0.01 ~ 0.1 Im) or Li ₂ Mn ₃ MO ₈ (where, M = Fe, Co, Ni, Cu, or Zn); A lithium manganese composite oxide having a spinel structure represented by LiNi _x Mn _2-x O ₄ ; LiMn ₂ O _{4 in} which a part of Li in the formula is substituted with an alkaline earth metal ion; Disulfide compounds; Fe ₂ (MoO ₄ ) ₃ , and the like, but is not limited thereto.

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

The conductive material is usually added in an amount of 1 to 50% by weight based on the total weight of the mixture including the cathode active material. Such a conductive material is not particularly limited as long as it has electrical conductivity without causing chemical changes in the battery, for example, graphite such as natural graphite or artificial graphite; Carbon black such as carbon black, acetylene black, ketjen black, channel black, furnace black, lamp black, and summer black; Conductive fibers such as carbon fiber and metal fiber; Metal powders such as carbon fluoride, aluminum, and nickel powder; Conductive whiskey such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.

On the other hand, the graphite based material having elasticity may be used as a conductive material, and may be used together with the materials.

The binder is a component that assists in bonding of the active material and the conductive material and bonding to the current collector, and is usually added in an amount of 1 to 50 wt% based on the total weight of the mixture containing the cathode active material. Examples of such binders include polyvinylidene fluoride, polyvinyl alcohol, carboxymethylcellulose (CMC), starch, hydroxypropylcellulose, regenerated cellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene , Polypropylene, ethylene-propylene-diene terpolymer (EPDM), sulfonated EPDM, styrene butylene rubber, fluorine rubber, various copolymers and the like.

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

The present invention also provides a secondary battery comprising the electrode, wherein the secondary battery may be a lithium ion battery, a lithium ion polymer battery, or a lithium polymer battery.

The lithium secondary batteries generally include an anode, a cathode, a separator interposed between the anode and the cathode, and a non-aqueous electrolyte containing a lithium salt. Other components of the lithium secondary battery will be described below.

The negative electrode is manufactured by applying, drying and pressing an anode active material on an anode current collector, and may optionally further include a conductive material, a binder, a filler, and the like as described above.

The negative electrode active material may include, for example, carbon such as non-graphitized carbon or graphite carbon; _{Li x Fe 2 O 3 (0≤x≤1} ), Li x WO 2 (0≤x≤1), Sn x Me 1-x Me 'y O z (Me: Mn, Fe, Pb, Ge; Me' : Metal complex oxides such as Al, B, P, Si, Group 1, Group 2, Group 3 elements of the periodic table, Halogen, 0 &lt; x &lt; Lithium metal; Lithium alloy; Silicon-based alloys; Tin alloy; _{SnO, SnO 2, PbO, PbO} 2, Pb 2 O 3, Pb 3 O 4, Sb 2 O 3, Sb 2 O 4, Sb 2 O 5, GeO, GeO 2, Bi 2 O 3, Bi 2 O 4, and Bi ₂ O ₅ ; Conductive polymers such as polyacetylene; Li-Co-Ni-based materials; Titanium oxide; Lithium titanium oxide and the like can be used, and in particular, a carbon-based material and / or Si can be included.

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

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

The lithium salt-containing nonaqueous electrolyte is composed of a nonaqueous electrolyte and lithium. Nonaqueous organic solvents, organic solid electrolytes, inorganic solid electrolytes, and the like are used as the nonaqueous electrolyte, but the present invention is not limited thereto.

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

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

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

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

The lithium salt-containing non-aqueous electrolyte may further contain, for the purpose of improving charge / discharge characteristics, flame retardancy, etc., for example, pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, glyme, N, N-substituted imidazolidine, ethylene glycol dialkyl ether, ammonium salt, pyrrole, 2-methoxyethanol, aluminum trichloride, etc. May be added. In some cases, halogen-containing solvents such as carbon tetrachloride and ethylene trifluoride may be further added to impart nonflammability. In order to improve the high-temperature storage characteristics, carbon dioxide gas may be further added. FEC (Fluoro-Ethylene Carbonate, PRS (Propene sultone), and the like.

In one specific _{example, LiPF 6, LiClO 4, LiBF} 4, LiN (SO 2 CF 3) 2 , such as a lithium salt, a highly dielectric solvent of DEC, DMC or EMC Fig solvent cyclic carbonate and a low viscosity of the EC or PC of And then adding it to a mixed solvent of linear carbonate to prepare a lithium salt-containing non-aqueous electrolyte.

The present invention can also provide a battery pack including the lithium secondary battery.

Further, it is possible to provide a device using the battery pack as an energy source.

As described above, the electrode active material according to the present invention can provide an electrode active material having an effect of improving low temperature output and energy density, and a lithium secondary battery including the electrode active material.

FIG. 1 is a graph showing discharge characteristics according to Experimental Example 1. FIG.

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

&Lt; Example 1 >

A lithium manganese-based oxide having the required transition comprises a layered crystal structure, and Mn as _{metal, 0.5Li 2 MnO 3 · 0.5Li (} Ni 0.45 Mn 0.35 Co 0.20) O 2 and a lithium iron phosphate having an olivine structure, on the surface An electrode active material prepared by mixing LiFePO ₄ having a coating layer composed of acetylene black particles in an 8: 2 ratio as a cathode active material was coated on an Al foil having a thickness of 20 탆 to an 80 탆 thickness, followed by rolling and drying, Respectively.

Lithium metal was used as the cathode, coated on a copper foil with a thickness of 20 ㎛ to a thickness of 80 ㎛, rolled and dried to prepare a negative electrode.

An electrode assembly was manufactured through a separator (CELLGUARD ^TM , thickness: 20 mu m) between the cathode and the anode. The electrode assembly was housed in a pouch-shaped battery case. Ethyl carbonate, dimethyl carbonate and ethyl methyl carbonate A pouch-type battery having a size of 30 mm * 40 mm was prepared by adding a lithium non-aqueous electrolyte containing 1 M LiPF ₆ as a lithium salt at a volume ratio of 1: 1: 1.

&Lt; Example 2 >

A pouch-shaped battery was produced in the same manner as in Example 1 except that artificial graphite was used instead of Li metal as a negative electrode.

&Lt; Comparative Example 1 &

A pouch-type battery was produced in the same manner as in Example 1 except that 0.5 Li ₂ MnO ₃ 0.5 Li (Ni _0.45 Mn _0.35 Co _0.20 ) O ₂ alone was used in the positive electrode active material Respectively.

&Lt; Comparative Example 2 &

A pouch-shaped battery was produced in the same manner as in Comparative Example 1, except that artificial graphite was used instead of Li metal as a negative electrode.

<Experimental Example 1>

The pouch-type battery manufactured in Example 1 and Comparative Example 1 was subjected to a discharge test at 25 ^° C by flowing a current of 0.1 C-rate at a voltage range of 4.65 V to 2.75 V. Table 1 below shows the nominal voltage during discharge. 1 shows the discharge profile.

4.65 V ~ 2.75 V Discharge Nominal Voltage (V) Example 1 3.746 V Comparative Example 1 3.735 V

According to Table 1 and FIG. 1, in the case of the battery of Example 1 in which lithium manganese oxide and lithium iron phosphate were mixed, the battery of Comparative Example 1 using lithium manganese oxide alone was superior in discharge characteristics and Nominal It is confirmed that the voltage value is improved and shows excellent energy density.

<Experimental Example 2>

The pouch type battery prepared in Example 2 and Comparative Example 2 was activated by flowing a current of 0.1 C-rate in a voltage range of 4.6 V to 2.5 V and then a charging current of 0.5 C-rate was flowed in the range of 4.4 V to 2.5 V The cell resistance was measured by flowing a discharge current of 0.5 C-rate at 25 ^o C for 1 hour to make a DOD50 state at 25 ^o C and a 1 C-rate current at -10 ^o C for 10 s. Table 2 below shows the resistance and output results in the DOD50 state.

The resistance (ohm) Output from DOD50 (W) Example 2 5.4 0.55 Comparative Example 2 6.1 0.49

According to the above Table 2, in the case of the battery of Example 1 in which the lithium manganese oxide and lithium iron phosphate were mixed, the resistance measurement result was lower than that of the battery of Comparative Example 1 in which the lithium manganese oxide alone was used, It can be confirmed that the low-temperature output characteristic is improved.

It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

Claims (24)

A lithium metal oxide particle represented by the following formula (2); And
A lithium metal phosphate particle represented by the following chemical formula (3)
The compound represented by the formula (2) has an average particle diameter (D50) in the range of 1 占 퐉 or more to 15 占 퐉 or less,
The compound represented by the formula (3) has an average particle diameter (D50) in the range of not less than 100 nm and not more than 2 m,
Wherein the lithium metal oxide is a secondary particle composed of primary particles and the secondary particle has a porosity in a range of 10% or more to 50% or less,
Wherein the lithium metal phosphate is a secondary particle composed of primary particles and the secondary particle has a porosity in a range of 10% or more to 50% or less.

_{(1-x) LiM'O 2 -xLi} 2 MnO 3 (2)
In this formula,
M 'is Mn _a M _b ;
M is one or more selected from the group consisting of Ni, Ti, Co, Al, Cu, Fe, Mg, B, Cr, Zr, Zn and two period transition metals;
0 &lt; x &lt;1; 0.5? A? 1.0; 0? B? 0.5; a + b = 1.

Li1 ₊ aFe1 _-xM &quot; _x (PO4 _-b ) _Xb (3)
In this formula,
M &quot; is at least one selected from Al, Mg and Ti,
X is at least one selected from F, S and N,
-0.5? A? + 0.5, 0? X? 0.5, and 0? B? delete delete delete delete The electrode active material according to claim 1, wherein the compound represented by the formula (2) has a spherical shape. The electrode active material according to claim 1, wherein the compound represented by the formula (3) has a spherical shape. The electrode active material according to claim 1, wherein the mixing ratio of the lithium metal oxide particles to the lithium metal phosphate is in the range of 3: 7 to 9: 1. The electrode active material according to claim 1, wherein the electrode active material further comprises a conductive coating layer existing on the surface of the lithium metal oxide. The electrode active material according to claim 9, wherein the conductive coating layer comprises at least one conductive particle. The electrode active material according to claim 9, wherein the conductive coating layer has a thickness in a range of 10 nm or more to 2 占 퐉 or less. The electrode active material according to claim 1, wherein the electrode active material further comprises a conductive coating layer present on the surface of the lithium metal phosphate. 13. The electrode active material according to claim 12, wherein the conductive coating layer comprises at least one conductive particle. The electrode active material according to claim 12, wherein the conductive coating layer has a thickness in a range of 10 nm or more to 500 nm or less. The electrode active material according to claim 9 or 12, wherein the conductive coating layer comprises conductive carbon black. 16. The electrode active material according to claim 15, wherein the conductive carbon black is at least one selected from the group consisting of acetylene black, Ketjen black, furnace black, oil-furnace black, Columbia carbon, channel black, lamp black, . delete delete A lithium secondary battery comprising the electrode active material according to claim 1 as a positive electrode active material. The lithium secondary battery according to claim 19, wherein the lithium secondary battery comprises a carbon-based material, Si, or a carbon-based material and Si as a negative electrode active material. The lithium secondary battery according to claim 19, wherein the lithium secondary battery is one selected from the group consisting of a lithium ion battery, a lithium ion polymer battery, and a lithium polymer battery. A battery pack comprising the lithium secondary battery according to claim 19. A device according to claim 22, wherein the battery pack is used as an energy source. delete

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