KR20130117731A - The electrodes for secondary battery and the secondary battery comprising the same - Google Patents

Abstract

PURPOSE: An electrode for a secondary battery has optimum electron conductivity by restricting the thickness of electrode slurry according to the particle size of an electrode active material, thereby providing a secondary battery with reduced internal resistance, excellent output performance, and charging rate. CONSTITUTION: An electrode for a secondary battery is that an electrode mixture including an electrode active material, a binder, and a conducting agent is spread on a current collector. The electrode active material is a positive active material and/or a negative active material the average particle diameter of the secondary particle (D_50) is 0.01-30 micron. The positive active material includes an oxide represented by chemical formula 1: Li_xM_yMn_(2-y)O_(4-z)A_z. The negative active material includes an oxide represented by chemical formula 2: Li_aM'_bO_(4-c)A_c. The electrode mixture is spread on a current thickness by 10-500 micron.

Description

Electrode for secondary battery and secondary battery comprising same {The Electrodes For Secondary Battery and the Secondary Battery Comprising the Same}

The present invention is an electrode for secondary batteries in which an electrode mixture including an electrode active material, a binder, and a conductive material is coated on a current collector, the electrode active material comprising: a positive electrode active material having an average particle diameter (D50) of secondary particles of 0.01 to 30 μm; / Or a negative electrode active material, the positive electrode active material comprises an oxide represented by the following formula (1), the negative electrode active material comprises an oxide of the formula (2), the electrode mixture is applied to the current collector to a thickness of 10 to 500 ㎛ It provides a secondary battery electrode and a secondary battery comprising the same.

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

Wherein 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.

Li _a M ' _b O _4-c A _c (2)

In the above formula, M 'is at least one element selected from the group consisting of Ti, Sn, Cu, Pb, Sb, Zn, Fe, In, Al and Zr; a and b are 0.1? a? 4; Is determined according to the oxidation number of M 'in the range of 0.2? B? 4; c is determined according to the oxidation number in the range of 0? c <0.2; A is one or more of an anion of -1 or -2.

The increase in the price of energy sources due to the depletion of fossil fuels, the increase of interest in environmental pollution, and the demand for environmentally friendly alternative energy sources are becoming indispensable factors for future life. Various researches on power generation technologies such as nuclear power, solar power, wind power, and tidal power have been continuing, and electric power storage devices for more efficient use of such generated energy have also been attracting much attention.

Particularly, in the case of a lithium secondary battery, the demand for an energy source is rapidly increasing due to an increase in technology development and demand for a mobile device. Recently, the use of a lithium secondary battery as a power source for an electric vehicle (EV) and a hybrid electric vehicle , And the area of use is also expanding for applications such as power assisted power supply through gridization.

In general, a lithium secondary battery has a structure in which a lithium electrolyte is impregnated into an electrode assembly including a cathode including a lithium transition metal oxide, a cathode including a carbon-based active material, and a porous separator. The positive electrode is prepared by coating a positive electrode mixture containing a lithium transition metal oxide on an aluminum foil, and the negative electrode is prepared by coating a negative electrode mixture including a carbon-based active material on a copper foil.

Increasing the amount of solids in the slurry can improve the capacity characteristics of the battery, but due to the relatively thick electrode, the electron conduction passage is increased, resulting in an increase in the resistance, thereby reducing the output characteristics. have.

In addition, the smaller the particle size of the active material in the slurry increases the packing density (packing density), the relatively thicker the electrode thickness to the same weight, the smaller the particle size may further lower the output characteristics of the battery.

Therefore, there is a very high need for a technology capable of improving the performance of the secondary battery by appropriately adjusting the thickness of the electrode relative to the particle size of the active material.

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

The inventors of the present application, after repeated in-depth studies and various experiments, desire to use an electrode for secondary batteries in which an electrode mixture containing an electrode active material having a particle size of 0.01 to 30 μm is applied to a thickness of 10 to 500 μm. It confirmed that the effect to achieve can be achieved and came to complete this invention.

Accordingly, the present invention is an electrode for secondary batteries in which an electrode mixture including an electrode active material, a binder, and a conductive material is coated on a current collector, wherein the electrode active material is a cathode active material having an average particle diameter (D50) of secondary particles of 0.01 to 30 μm. And / or a negative electrode active material, the positive electrode active material includes an oxide represented by the following Chemical Formula 1, and the negative electrode active material includes an oxide of the following Chemical Formula 2, and the electrode mixture is applied to a current collector with a thickness of 10 to 500 μm. It provides a secondary battery electrode, characterized in that.

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

Wherein 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.

Li _a M ' _b O _4-c A _c (2)

In the above formula, M 'is at least one element selected from the group consisting of Ti, Sn, Cu, Pb, Sb, Zn, Fe, In, Al and Zr; a and b are 0.1? a? 4; Is determined according to the oxidation number of M 'in the range of 0.2? B? 4; c is determined according to the oxidation number in the range of 0? c <0.2; A is one or more of an anion of -1 or -2.

As described above, since the packing density increases as the size of the active material particles is smaller, the electrode thickness may be thicker than the same weight. In this case, since the electron conduction path becomes longer, the resistance may increase, thereby degrading the performance of the secondary battery.

Thus, the electrode for secondary batteries according to the present invention may exhibit excellent output characteristics because it limits the thickness of the slurry to be applied to the current collector according to the particle size of the electrode active material, thereby exhibiting optimum electronic conductivity.

As the particle diameter of the cathode active material is smaller, the coating thickness on the current collector may be thinner.

Specifically, when the secondary particle average particle diameter (D50) of the electrode active material is 0.1 µm or more and less than 1 µm, the electrode mixture has a thickness of 10 to 40 µm; When the secondary particle average particle diameter (D50) is 1 µm or more and less than 3 µm, the electrode mixture is 10 to 60 µm thick; When the secondary particle average particle diameter (D50) is 3 µm or more and less than 5 µm, the electrode mixture has a thickness of 10 to 100 µm; When the secondary particle average particle diameter (D50) is 5 µm or more and less than 7 µm, the electrode mixture has a thickness of 10 to 140 µm; When the secondary particle average particle diameter (D50) is 7 µm or more and less than 10 µm, the electrode mixture has a thickness of 10 to 190 µm; When the secondary particle average particle diameter (D50) is 10 µm or more and less than 15 µm, the electrode mixture has a thickness of 10 to 270 µm; When the secondary particle average particle diameter (D50) is 15 μm or more and less than 20 μm, the electrode mixture may be applied to the current collector in a thickness of 10 to 370 μm.

Since the average particle diameter of the secondary battery and the coating thickness of the electrode mixture according to the above-defined ranges are in order to achieve the desired optimum effect in the present invention, the pore rate of the active material may be affected if this occurs, thereby causing a problem of electrode adhesion strength. In addition, the conductivity of the electrode may be increased, which may increase the resistance of the battery.

That is, as the particle size of the active material decreases, the packing density increases, so that the coating thickness of the positive electrode mixture including the same decreases to the current collector, thereby not only reducing the output characteristics of the battery, but also the electrode per weight. Since the volume of is reduced, there is an advantage that can reduce the volume of the entire cell.

The secondary particle average particle diameter (D50) of the oxide in the present invention means a particle diameter when a plurality of primary particles are aggregated to form one combination. The positive electrode active material tends to aggregate one primary particle with each other according to the setting conditions of the manufacturing process to form one combination, and such agglomerated combination exhibits active material properties by itself. Therefore, the secondary particle average particle diameter of the oxide preferably means the particle diameter of such agglomeration agent. The average particle diameter (D50) of the primary particles may be, for example, 0.01 to 5 ㎛.

As the cathode active material, the oxide of Formula 1 may be represented by the following Formula 3.

Li _x Ni _y Mn _2-y O ₄ (3)

Wherein 0.9 ≦ x ≦ 1.2, 0.4 ≦ y ≦ 0.5;

More specifically, the oxide of Formula 3 may be LiNi _0.5 Mn _1.5 O ₄ or LiNi _0.4 Mn _1.6 O ₄ .

As an anode active material, the oxide of Formula 2 may be an oxide represented by the following Formula 4.

Li _a Ti _b O ₄ (4)

Wherein a and b are 0.1 ≦ a ≦ 4; 0.2≤b≤4.

More specifically, the oxide of Formula 4 may be Li _1.33 Ti _1.67 O ₄ or LiTi ₂ O ₄ .

Due to the high potential of the lithium titanate oxide, a spinel lithium manganese composite oxide having a relatively high potential of LiNi _x Mn _2-x O ₄ (x = 0.01 to 0.6) may be used as a cathode active material.

The present invention also provides a secondary battery comprising the electrode for secondary batteries.

The secondary battery according to the present invention includes a cathode prepared by applying a mixture of a cathode active material, a conductive material, and a binder on a cathode current collector, followed by drying and pressing, and a cathode manufactured using the same method, in which case, In some cases, a filler may be further added to the mixture.

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 positive electrode active material may be a material defined above, for example, further, a layered compound such as lithium cobalt oxide (LiCoO ₂ ), lithium nickel oxide (LiNiO ₂ ) or a compound substituted with one or more transition metals; 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); 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 can be used.

The conductive material may further include the aforementioned carbon nanotube or graphene new material. Such materials may be added in an amount of 1 to 20% by weight based on the weight of the positive electrode mixture including the positive electrode active material, and are not particularly limited as long as they are conductive without causing chemical changes in the battery. For example, natural graphite Graphite, such as 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 whiskeys such as zinc oxide and potassium titanate; Conductive metal oxides such as titanium oxide; Conductive materials such as polyphenylene derivatives and the like can be used.

The binder is a component 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, and various copolymers.

The filler is optionally used as a component for suppressing 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-based polymerizers such as polyethylene and polypropylene; Fibrous materials such as glass fibers and carbon fibers are used.

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 negative electrode active material may be a material defined above, for example, carbon, such as non-graphitized carbon, graphite-based 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 can be used.

The secondary battery may have a structure in which a lithium salt-containing electrolyte is impregnated in an electrode assembly having a separator interposed between a positive electrode and a negative electrode.

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 electrolyte solution containing the lithium salt is composed of an electrolyte solution and a lithium salt. The electrolyte solution may be a non-aqueous organic solvent, an organic solid electrolyte, or an inorganic solid electrolyte, but 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.

As the inorganic solid electrolyte, for example, 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, sulfates, and the like of Li, such as Li ₄ SiO ₄ -LiI-LiOH, Li ₃ PO ₄ -Li ₂ S-SiS ₂ , and the like, may 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.

For the purpose of improving the charge / discharge characteristics and the flame retardancy, the electrolytic solution is preferably mixed with an organic solvent such as pyridine, triethylphosphite, triethanolamine, cyclic ether, ethylenediamine, glyme, Benzene derivatives, sulfur, quinone imine dyes, N-substituted oxazolidinones, N, N-substituted imidazolidines, ethylene glycol dialkyl ethers, ammonium salts, pyrrole, 2-methoxyethanol, . In some cases, 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 example, lithium salts such as LiPF ₆ , LiClO ₄ , LiBF ₄ , LiN (SO ₂ CF ₃ ) _2, and the like, are linear with cyclic carbonates of EC or PC, which are highly dielectric solvents, and DEC, DMC, or EMC, which are low viscosity solvents. The lithium salt-containing non-aqueous electrolyte can be prepared by adding to a mixed solvent of carbonate.

The present invention also provides a battery module including the secondary battery as a unit cell, and a battery pack including the battery module.

The battery pack can be used as a power source for a medium and large-sized device requiring high temperature stability, long cycle characteristics, and high rate characteristics.

Examples of the medium-large device include a power tool that is driven by an electric motor; An electric vehicle including an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and the like; An electric motorcycle including an electric bike (E-bike) and an electric scooter (E-scooter); An electric golf cart; And a power storage system, but the present invention is not limited thereto.

As described above, the secondary battery electrode according to the present invention limits the thickness of the electrode slurry applied to the current collector according to the particle size of the electrode active material, and thus exhibits optimum electronic conductivity, so that the secondary battery including the same reduces the internal resistance. Therefore, it shows excellent output characteristics and charging speed.

&Lt; Example 1 >

90% by weight of LiNi _0.5 Mn _1.5 O ₄ (positive electrode active material), 5% by weight of Super-p (conductor) and 5% by weight of PVdF (binder) were added to NMP to prepare a positive electrode mixture. Prepared. The positive electrode mixture was applied to an aluminum current collector with a thickness of 43.05 μm, dried, and pressed to prepare a secondary battery positive electrode.

<Example 2>

In Example 1, LiNi _0.5 Mn _1.5 O ₄ (anode active material) having an average particle diameter of 4.32 μm was prepared, and a positive electrode mixture was prepared, except that it was applied to an aluminum current collector at a thickness of 46.84 μm. A positive electrode for a secondary battery was manufactured in the same manner as in Example 1.

<Example 3>

In Example 1, LiNi _0.5 Mn _1.5 O ₄ (anode active material) having an average particle diameter of 8.57 μm was prepared to prepare a positive electrode mixture, except that it was applied to an aluminum current collector with a thickness of 51.56 μm. A positive electrode for a secondary battery was manufactured in the same manner as in Example 1.

&Lt; Comparative Example 1 &

In Example 1, LiNi _0.5 Mn _1.5 O ₄ (anode active material) having an average particle diameter of 31.16 μm was prepared, and a positive electrode mixture was prepared, except that it was applied to an aluminum current collector with a thickness of 502.56 μm. A positive electrode for a secondary battery was manufactured in the same manner as in Example 1.

<Experimental Example 1>

The porosity of the cathodes prepared in Examples 1 to 3 and Comparative Example 1 was measured and shown in Table 1 below.

Particle size (μm) Electrode Coating Thickness (㎛) Porosity (%) Example 1 2.12 43.05 28 Example 2 4.32 46.84 31 Example 3 8.57 51.56 35 Comparative Example 1 31.16 502.56 62

According to Table 1, the positive electrodes of Examples 1 to 3, it can be seen that the porosity is very small compared to the battery of Comparative Example 1. The optimum porosity corresponding to Examples 1 to 3 of Table 1 may be determined by the resistance of the battery.

<Experimental Example 1>

The negative electrode mixture was prepared by adding the positive electrode prepared in Examples 1 to 3 and Comparative Example 1, 93.5% by weight of Li _1.33 Ti, _1.67 O ₄ , 2% by weight of Super-C (conductor) and 4.5% by weight of PVdF (binder) to NMP. After the preparation, the electrode assembly was prepared using a porous separator made of a negative electrode and polypropylene prepared by coating, drying and pressing on an aluminum current collector. Thereafter, the electrode assembly was placed in a pouch, and the lead wires were connected to each other, whereby 1 M of LiPF ₆ salt was dissolved in a volume ratio of 1: 1, ethylene carbonate (EC), dimethyl carbonate (DMC), and ethyl methyl carbonate (EMC). ) Was injected into the electrolyte, and then sealed to assemble a lithium secondary battery. The conversion resistance is measured based on the 5Ah capacity of the secondary battery and is shown in Table 2 below.

Particle size (μm) Electrode Coating Thickness (㎛) 10 s resistance (mΩ) Example 1 2.12 43.05 2.21 Example 2 4.32 46.84 2.38 Example 3 8.57 51.56 2.89 Comparative Example 1 31.16 502.56 7.14

According to Table 2, in the case of the batteries of Examples 1 to 3, the packing density increases according to the particle size, so that the coating thickness becomes thin, so that the resistance of the battery decreases as compared with the battery of Comparative Example 1.

Those skilled in the art to which the present invention pertains will be able to exercise various applications and modifications within the scope of the present invention based on the above contents.

Claims (19)

An electrode for secondary batteries in which an electrode mixture including an electrode active material, a binder, and a conductive material is coated on a current collector, wherein the electrode active material has a positive electrode active material and / or a negative electrode active material having an average particle diameter (D50) of the secondary particles of 0.01 to 30 μm. The positive electrode active material includes an oxide represented by the following Chemical Formula 1, and the negative electrode active material includes an oxide of the following Chemical Formula 2, and the electrode mixture is applied to a current collector in a thickness of 10 to 500 μm. Secondary battery electrode:
Li _x M _y Mn _{2 - y} O _{4 - z z} (1)
Wherein 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.
Li _a M ' _b O _4-c A _c (2)
In the above formula, M 'is at least one element selected from the group consisting of Ti, Sn, Cu, Pb, Sb, Zn, Fe, In, Al and Zr; a and b are 0.1? a? 4; Is determined according to the oxidation number of M 'in the range of 0.2? B? 4; c is determined according to the oxidation number in the range of 0? c <0.2; A is one or more of an anion of -1 or -2. 2. The secondary battery according to claim 1, wherein the secondary particle average particle diameter (D50) of the electrode active material is 0.1 µm or more and less than 1 µm, and the electrode mixture is applied to the current collector in a thickness of 10 to 40 µm. electrode. 2. The secondary battery according to claim 1, wherein the secondary particle average particle diameter (D50) of the electrode active material is 1 µm or more and less than 3 µm, and the electrode mixture is applied to the current collector with a thickness of 10 to 60 µm. electrode. 2. The secondary battery according to claim 1, wherein the secondary particle average particle diameter (D50) of the electrode active material is 3 µm or more and less than 5 µm, and the electrode mixture is applied to the current collector in a thickness of 10 to 100 µm. electrode. The secondary battery average particle diameter (D50) of the electrode active material is a secondary battery, characterized in that the electrode mixture is applied to the current collector in a thickness of 10 to 140 ㎛. electrode. The secondary battery average particle diameter (D50) of the electrode active material is a secondary battery, characterized in that the electrode mixture is applied to the current collector in a thickness of 10 to 190 ㎛. electrode. The secondary particle average particle diameter (D50) of the electrode active material is a secondary battery, characterized in that the electrode mixture is applied to the current collector in a thickness of 10 to 270 ㎛. electrode. The secondary particle average particle diameter (D50) of the electrode active material is a secondary battery, characterized in that the electrode mixture is applied to the current collector in a thickness of 10 to 370 ㎛. electrode. The secondary battery electrode of claim 1, wherein the primary particle average particle diameter (D50) of the electrode active material is 0.01 to 5 μm. The method of claim 1, wherein the oxide of Formula 1 is a secondary battery electrode, characterized in that represented by the formula (3).
Li _x Ni _y Mn _2-y O ₄ (3)
In the above formula, 0.9? X? 1.2 and 0.4? Y? 0.5. The electrode of claim 10, wherein the oxide is LiNi _0.5 Mn _1.5 O ₄ or LiNi _0.4 Mn _1.6 O ₄ . The method of claim 1, wherein the oxide of Formula 2 is a secondary battery electrode, characterized in that represented by the formula (4):
Li _a Ti _b O ₄ (4)
Wherein a and b are 0.1 ≦ a ≦ 4; 0.2≤b≤4. The electrode of claim 12, wherein the oxide of Formula 4 is represented by Li _1.33 Ti _1.67 O ₄ or LiTi ₂ O ₄ . A secondary battery comprising the secondary battery electrode according to any one of claims 1 to 13. The secondary battery of claim 14, wherein the secondary battery is a lithium secondary battery. A battery module comprising the secondary battery according to claim 15 as a unit cell. A battery pack comprising the battery module according to claim 16. A device comprising a battery pack according to claim 17. 19. The device of claim 18, wherein the device is an electric vehicle, a hybrid electric vehicle, a plug-in hybrid electric vehicle, or a system for power storage.