KR102144326B1 - Active material for secondary battery, Method for preparing the same, and Secondary battery comprising the same - Google Patents

Abstract

The present invention provides an active material for a secondary battery and a secondary battery including the same. The active material for a secondary battery is represented by chemical formula 1, M_aCuS_xO_yF_b. In chemical formula (1), M is a group 1 alkali metal, x is an integer from 1 to 5, y is an integer from 2 to 9, and a and b may independently be 0 or 1. According to the present invention, an active material for a secondary battery and a secondary battery including the same may have high capacity and high energy density characteristics while being based on conversion reaction.

Description

Active material for secondary battery, method for manufacturing the same, and secondary battery including the same {Active material for secondary battery, Method for preparing the same, and Secondary battery comprising the same}

The present invention relates to a secondary battery, and more particularly, to a secondary battery including an active material for a secondary battery.

Secondary battery refers to a battery that can be used repeatedly because it can be charged as well as discharge. In a typical lithium secondary battery among secondary batteries, lithium ions contained in the positive electrode active material are transferred to the negative electrode through the electrolyte, and then inserted into the layered structure of the negative electrode active material (charging), and then the lithium ions inserted into the layered structure of the negative electrode active material are again It works through the principle of returning to the anode (discharge). These lithium secondary batteries are currently commercialized and used as small power sources such as mobile phones and notebook computers, and are predicted to be usable as large power sources such as hybrid vehicles, and their demand is expected to increase.

However, the composite metal oxide, which is mainly used as a positive electrode active material in lithium secondary batteries, contains rare metal elements such as lithium, and thus there is a fear that the supply of resources will be limited in light of the limited and ubiquitous reserves of resources. There is a fear of not being able to respond to the increase.

Accordingly, studies on sodium secondary batteries using sodium as well as lithium as a positive electrode active material are being conducted. This is because the supply of sodium is abundant and the price is low. In particular, efforts to implement similar performance to lithium secondary batteries by simply replacing lithium with sodium in the existing lithium secondary battery system are continuing. Therefore, many studies have been conducted on electrode active materials based on intercalation and deintercalation of sodium ions in the electrode. However, sodium ions have a relatively larger ionic radius than lithium ions, and thus have a disadvantage in that charging/discharging performance is deteriorated due to poor insertion into the structure, desorption to the outside, and diffusivity of ions within the structure. Therefore, despite the advantage of low price, the materials of the sodium electrode active material based on insertion and removal have limitations in manufacturing a secondary battery having high capacity and energy density characteristics.

Republic of Korea Patent Publication No. 2012-0133300

The problem to be solved by the present invention is to provide an active material for a secondary battery based on a conversion reaction and a secondary battery with improved electrochemical properties using the same.

The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems that are not mentioned will be clearly understood by those skilled in the art from the following description.

In order to achieve the technical problem, an embodiment of the present invention provides an active material for a secondary battery. The active material for a secondary battery may be represented by Chemical Formula 1.

The active material for a secondary battery represented by Formula 1 may be Formula 2 below.

M in Formula 1 may be lithium (Li) or sodium (Na).

S _x O _y in Formula 1 may be an anion having a charge of -2 as sulfur oxyanions.

The sulfur oxygenate anion is SO ₃ ^2- (sulfite), SO ₄ ^2- (sulfate), S ₂ O ₃ ^2- (thiosulfate), S ₂ O ₄ ^2- (dithionite), S ₂ O ₅ ^2- (disulfite) , S ₂ O ₆ ^2- (dithionate), S ₂ O ₇ ^2- (disulfate), S ₂ O ₈ ^2- (peroxydisulfate) or S ₄ O ₆ ^2- (tetrathionate).

The particle size of the active material for a secondary battery may be a nano size.

In order to achieve the technical problem, another embodiment of the present invention provides a method of manufacturing an electrode for a secondary battery. The method of manufacturing an electrode for a secondary battery includes mixing an active material for a secondary battery containing sulfur oxyacid anion and a conductive material, grinding and mixing the active material-conductive material composite for secondary batteries by a milling process, and mixing the composite and a binder. It may include preparing a slurry and applying and drying the slurry to a current collector.

The active material for a secondary battery including the sulfur oxygen anion may include an active material for a secondary battery represented by Formula 1 below.

The milling process may be a high energy ball mill, a planetary mill, a stirred ball mill, or a vibrating mill.

The milling process may be performed at a speed of 400 to 800 rpm.

The milling process may be performed for 10 to 24 hours.

In order to achieve the technical problem, another embodiment of the present invention provides a secondary battery. The secondary battery may include a positive electrode including an active material for a secondary battery represented by Formula 1 below, a negative electrode containing a negative electrode active material, and an electrolyte disposed between the positive electrode and the negative electrode.

As described above, the active material for a secondary battery and a secondary battery including the same according to the present invention may have high capacity and high energy density characteristics while using a conversion reaction base.

However, the effects of the present invention are not limited to the effects mentioned above, and other effects that are not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a schematic diagram showing a secondary battery according to an embodiment of the present invention.
2 is a graph showing charge and discharge characteristics according to C-rate of a secondary battery manufactured according to a secondary battery manufacturing example.
3 is a graph showing charge/discharge characteristics of a secondary battery manufactured according to a secondary battery manufacturing example at a current charge/discharge rate C/50-rate.
4 is a graph showing charge/discharge capacity and Coulomb efficiency according to the number of cycles of a secondary battery manufactured according to a secondary battery manufacturing example.
5 is a graph showing charge/discharge characteristics according to C-rate of a secondary battery manufactured according to Comparative Example of a secondary battery.
6 is a graph showing charge and discharge capacity according to the number of cycles of a secondary battery manufactured according to the secondary battery manufacturing example.

In the present invention, various modifications may be made and various embodiments may be provided, and specific embodiments will be illustrated in the drawings and described in detail. However, this is not intended to limit the present invention to a specific embodiment, it is to be understood as including all changes, equivalents, and substitutes included in the spirit and scope of the present invention.

The terms used in the present application are only used to describe specific embodiments, and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In the present application, terms such as "comprise" or "have" are intended to designate the presence of features, numbers, steps, actions, components, parts, or combinations thereof described in the specification, but one or more other features. It is to be understood that the presence or addition of elements or numbers, steps, actions, components, parts, or combinations thereof does not preclude in advance.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which the present invention belongs. Terms as defined in a commonly used dictionary should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and should not be interpreted as an ideal or excessively formal meaning unless explicitly defined in this application. Does not.

Hereinafter, preferred embodiments of the present invention will be described in more detail with reference to the accompanying drawings. In describing the present invention, in order to facilitate an overall understanding, the same reference numerals are used for the same elements in the drawings, and duplicate descriptions for the same elements are omitted.

Active material for secondary battery

The active material for a secondary battery according to an embodiment of the present invention is represented by the following formula (1).

[Formula 1]

M _a CuS _x O _y F _b

In Formula 1, M may be a Group 1 alkali metal, for example, lithium (Li) or sodium (Na). a and b may each independently be 0 or 1. x may be an integer of 1 to 5, and as an example, may be 1, 2, 3, or 4. y may be an integer of 2 to 9, and as an example, it may be 2, 3, 4, 5, 6, 7 or 8. S _x O _y is sulfur oxyanions, and may be an anion having a charge of -2. As an example, SO ₃ ^2- (sulfite), SO ₄ ^2- (sulfate), S ₂ O ₃ ^2- (thiosulfate), S ₂ O ₄ ^2- (dithionite), S ₂ O ₅ ^2- (disulfite), It may be S ₂ O ₆ ^2- (dithionate), S ₂ O ₇ ^2- (disulfate), S ₂ O ₈ ^2- (peroxydisulfate), S ₄ O ₆ ^2- (tetrathionate).

According to an embodiment of the present invention, since the active material for a secondary battery represented by Formula 1 contains F, which is an element having a high electronegativity, an inductive effect can be maximized. Accordingly, the conversion reaction-based secondary battery can overcome a low oxidation-reduction potential, and thus the secondary battery including the alkali metal active material can have a high operating voltage.

In one example, the active material for a secondary battery may be represented by Formula 2 below.

[Formula 2]

M _a CuS _x O _y

In Formula 2, M may be a Group 1 alkali metal, for example, lithium (Li) or sodium (Na). a can be 0 or 1. x may be an integer of 1 to 5, and as an example, may be 1, 2, 3, or 4. y may be an integer of 2 to 9, and as an example, it may be 2, 3, 4, 5, 6, 7 or 8. S _x O _y is sulfur oxyanions, and may be an anion having a charge of -2. As an example, SO ₃ ^2- (sulfite), SO ₄ ^2- (sulfate), S ₂ O ₃ ^2- (thiosulfate), S ₂ O ₄ ^2- (dithionite), S ₂ O ₅ ^2- (disulfite), It may be S ₂ O ₆ ^2- (dithionate), S ₂ O ₇ ^2- (disulfate), S ₂ O ₈ ^2- (peroxydisulfate) or S ₄ O ₆ ^2- (tetrathionate).

More specifically, the positive active material may be represented by Formula 3 below.

[Chemical Formula 3]

M _a CuSO ₄

In Formula 3, M may be a Group 1 alkali metal, for example, lithium (Li) or sodium (Na). a can be 0 or 1.

The active material for a secondary battery described above may be used as a positive active material, or may be used as a negative active material.

Hereinafter, a secondary battery to which the positive active material can be applied will be described.

Secondary battery

1 is a schematic diagram showing a secondary battery according to an embodiment of the present invention.

Referring to FIG. 1, the secondary battery 100 includes a negative active material layer 120 containing a negative active material, a positive active material layer 140 containing a positive active material, and a separator 130 interposed therebetween. An electrolyte 160 may be disposed or charged between the negative active material layer 120 and the separator 130 and between the positive active material layer 140 and the separator 130. The negative active material layer 120 may be disposed on the negative current collector 110, and the positive active material layer 140 may be disposed on the positive current collector 150.

<Anode>

The positive electrode may be prepared by mixing the active material for a secondary battery, a conductive material, and a binder described above to obtain a positive electrode material.

priority. It may include mixing an active material for a secondary battery including a sulfur oxyacid anion and a conductive material. Accordingly, an active material for a secondary battery-conductive material composite can be obtained. According to an embodiment of the present invention, an active material for a secondary battery containing sulfur oxyacid anion is represented by the following formula (1).

[Formula 1]

M _a CuS _x O _y F _b

In addition, in an example, the positive electrode active material may be represented by the following Formula 2 or Formula 3.

[Formula 2]

M _a CuS _x O _y

[Chemical Formula 3]

M _a CuSO ₄

At this time, in Formulas 1, 2, and 3, M, a, x, y and/or b are as described in the active material for a secondary battery.

The conductive material is used to improve the conductivity of the electrode, and any material capable of imparting electronic conductivity properties without causing chemical changes in the secondary battery constructed according to the present invention may be used. Preferably, it may include one or a mixture of two or more selected from graphite-based materials, carbon-based materials, metal-based or metal compound-based materials, and conductive polymers. As an example of the graphite-based material, artificial graphite or natural graphite may be used. As an example of the carbon-based material, Super P carbon black, Ketjen black. It may be Denka black, acetylene black, carbon black, or the like. The metal-based or metal-compound-based material may be tin oxide, tin phosphate, titanium oxide, or perovskite material. In addition, the material of the conductive material is not limited thereto. In this case, the content of the conductive material may be appropriately adjusted and used, and as an example, the conductive material may be contained in an amount of 10 to 30 parts by weight based on 100 parts by weight of the positive electrode active material.

It may include the step of pulverizing and mixing the obtained active material for secondary battery-conductive material composite through a milling process. The milling process may be performed by a high energy ball mill, a planetary mill, a stirred ball mill, or a vibrating mill, but is not limited thereto and is generally used. A milling device or a milling method can be used.

The milling process may be performed at a speed of 400 to 800 rpm, and may be performed for 10 to 24 hours. As an example, it may be performed for 12 hours to 20 hours at a speed of 500 to 700 rpm. In the case of the mixing process speed and time, the average particle size of the positive electrode active material according to the exemplary embodiment of the present invention may be nanoparticles so that the conversion reaction can be performed quickly.

The active material-conductive material composite for a secondary battery is made into nanoparticles through a milling process, so that the surface area of the particles may increase as the particle size of the positive electrode active material-conductive material composite has a nano size. Accordingly, the positive electrode active material-conductive material composite particles accordingly induce a rapid conversion reaction in the secondary battery, thereby maximizing the electrochemical performance of the secondary battery.

The binder is a thermoplastic resin such as polyvinylidene fluoride, polytetrafluoroethylene, tetrafluoroethylene, vinylidene fluoride copolymer, fluorine resin such as propylene hexafluoride, and/or polyolefin resin such as polyethylene and polypropylene. Can include. The binder may be contained in an amount of 2 to 9 parts by weight based on 100 parts by weight of the positive electrode active material.

A slurry may be prepared by dissolving the obtained active material-conductive material composite and a binder in a solvent. The resulting slurry can be applied on a positive electrode current collector to form a positive electrode. The positive electrode current collector may be a conductor such as aluminum (Al), nickel (Ni), stainless steel (SUS), or molybdenum (Mo). Applying the slurry on the positive electrode current collector may be a method of forming a paste using pressure molding or an organic solvent, and then applying the paste on the current collector and pressing to fix it. Examples of the organic solvent include amines such as N,N-dimethylaminopropylamine and diethyltriamine; Ethers such as ethylene oxide and tetrahydrofuran; Ketone systems such as methyl ethyl ketone; Esters such as methyl acetate; It may be an aprotic polar solvent such as dimethylacetamide and N-methyl-2-pyrrolidone. Applying the paste onto the positive electrode current collector may be performed using, for example, a gravure coating method, a slit die coating method, a knife coating method, or a spray coating method.

<cathode>

The negative electrode active material is a metal that can cause a conversion reaction, a metal alloy, a metal oxide, a metal fluoride, a metal sulfide, and a carbon material such as natural graphite, artificial graphite, coke, carbon black, carbon nanotubes, graphene, etc. It can also be formed using.

A negative electrode material can be obtained by mixing a negative electrode active material, a conductive material, and a binder. In this case, the conductive material may be a carbon material such as natural graphite, artificial graphite, coke, carbon black, carbon nanotubes, and graphene. The binder is a thermoplastic resin such as polyvinylidene fluoride, polytetrafluoroethylene, tetrafluoroethylene, vinylidene fluoride copolymer, fluorine resin such as propylene hexafluoride, and/or polyolefin resin such as polyethylene and polypropylene. Can include.

A negative electrode material can be applied on the negative electrode current collector to form a negative electrode. The negative electrode current collector may be a conductor such as aluminum (Al), nickel (Ni), stainless steel (SUS), and molybdenum (Mo). Applying the negative electrode material on the positive electrode current collector may be performed by pressure molding or a method of making a paste using an organic solvent, etc., and then applying the paste onto the current collector and pressing to fix it. Examples of the organic solvent include amines such as N,N-dimethylaminopropylamine and diethyltriamine; Ethers such as ethylene oxide and tetrahydrofuran; Ketone systems such as methyl ethyl ketone; Esters such as methyl acetate; It may be an aprotic polar solvent such as dimethylacetamide and N-methyl-2-pyrrolidone. Applying the paste onto the negative electrode current collector may be performed using, for example, a gravure coating method, a slit die coating method, a knife coating method, or a spray coating method.

<Electrolyte>

The electrolyte may contain an alkali metal salt. The alkali metal salt may be MClO ₄ , MPF ₆ , MAsF ₆ , MSbF ₆ , MBF ₄ , MCF ₃ SO ₃ , MN(SO ₂ CF ₃ ) ₂ , lower aliphatic carboxylic acid alkali metal salt, MAlCl _4, etc., where M is an alkali The metal may be lithium (Li) or sodium (Na). Further, a mixture of two or more of these may be used. Among these, it is preferable to use an electrolyte containing fluorine. Further, the electrolyte can be dissolved in an organic solvent and used as a non-aqueous electrolyte. As the organic solvent, for example, propylene carbonate, ethylene carbonate, dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate, isopropyl methyl carbonate, vinylene carbonate, 4- Carbonates such as trifluoromethyl-1,3-dioxolan-2-one and 1,2-di(methoxycarbonyloxy)ethane; 1,2-dimethoxyethane, 1,3-dimethoxypropane, pentafluoropropylmethylether, 2,2,3,3-tetrafluoropropyldifluoromethylether, tetrahydrofuran, 2-methyltetrahydro Ethers such as furan; Esters such as methyl formate, methyl acetate, and γ-butyrolactone; Nitriles such as acetonitrile and butyronitrile; Amides such as N,N-dimethylformamide and N,N-dimethylacetamide; Carbamates such as 3-methyl-2-oxazolidone; Sulfur-containing compounds such as sulfolane, dimethyl sulfoxide, and 1,3-propane sultone; Alternatively, a fluorine substituent may be further introduced into the organic solvent described above.

Alternatively, a solid electrolyte may be used. The solid electrolyte may be an organic solid electrolyte such as a polyethylene oxide polymer compound, a polymer compound including at least one of a polyorganosiloxane chain, or a polyoxyalkylene chain. In addition, a so-called gel-type electrolyte in which a non-aqueous electrolyte is supported on a polymer compound can also be used. Meanwhile, 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 , Li ₄ SiO ₄ -LiI-LiOH, Li ₃ PO ₄ -Li ₂ S-SiS ₂ Li nitride, halide, sulfate, Na ₂ S-SiS ₂ , Na ₂ S-GeS ₂ , NaTi ₂ (PO ₄ ) ₃ , NaFe ₂ (PO ₄ ) ₃ , Na ₂ (SO ₄ ) ₃ , Fe ₂ (SO ₄ ) ₂ (PO ₄ ), Fe ₂ (MoO ₄ ) _{3 It} is also possible to use an inorganic solid electrolyte. In some cases, the safety of the secondary battery can be further improved by using these solid electrolytes. In addition, the solid electrolyte may serve as a separator to be described later, and in that case, a separator may not be required.

<Separator>

A separator may be disposed between the anode and the cathode. Such a separator may be a material having a form such as a porous film, a nonwoven fabric, or a woven fabric made of a material such as a polyolefin resin such as polyethylene or polypropylene, a fluorine resin, or a nitrogen-containing aromatic polymer. The thickness of the separator is preferably thinner as long as the mechanical strength is maintained from the viewpoint of increasing the bulk energy density of the battery and decreasing the internal resistance. The thickness of the separator may be generally 5 to 200 μm, and more specifically 5 to 40 μm.

<Method of manufacturing secondary battery>

After forming an electrode group by sequentially stacking a positive electrode, a separator, and a negative electrode, if necessary, the electrode group is rolled up and stored in a battery can, and a sodium secondary battery can be manufactured by impregnating the electrode group with a nonaqueous electrolyte. On the contrary, after forming an electrode group by stacking a positive electrode, a solid electrolyte, and a negative electrode, if necessary, the electrode group may be rolled up and stored in a battery can to manufacture a sodium secondary battery.

In the case of the secondary battery according to the present invention, it may be performed based on a conversion reaction in which alkali metal ions react with the structure itself during charging and discharging. The active material for a secondary battery according to the present invention may be converted into a metal Cu ⁰ and an alkali metal salt upon discharge, and may be reversibly converted into an active material for a secondary battery upon charging.

According to the charging and discharging of the active material for a secondary battery of Formula 1 according to the above embodiment, a conversion reaction may be performed as shown in Reaction Formula 1 below.

[Scheme 1]

M _a CuS _x O _y F _b + zM ⁺ + 2e ↔ Cu + M ₂ S _x O _y + bMF

At this time, in Reaction Formula 1, M, a, x, y, and b are the same as described for the active material for a secondary battery, and z is a coefficient for matching the stoichiometry.

As described above, in the case of an active material for a secondary battery based on a conversion reaction, there may be an advantage of storing more alkali metals than an active material for a secondary battery based on insertion and removal.

On the other hand, in the conversion reaction-based electrode, since rearrangement and decomposition of the structure are repeated due to chemical bonding with an alkali metal, it may be important to increase the surface area of the particles for easier charging and discharging. In contrast, the active material for a secondary battery according to an embodiment of the present invention may increase the surface area of the active material particles through a nanoparticle process through the milling process of the secondary battery active material-conductive material composite. Therefore, the secondary battery including the same can implement excellent characteristics. That is, since the secondary battery according to the present invention can have a high operating voltage, it is possible to obtain a secondary battery having a high energy density compared to the insertion and removal-based secondary battery.

Hereinafter, a preferred experimental example (example) is presented to aid the understanding of the present invention. However, the following experimental examples are only intended to aid understanding of the present invention, and the present invention is not limited by the following experimental examples.

[Experimental examples; Examples]

Anode Manufacturing Example

CuSO _4· 5H ₂ O was heat-treated at 500°C and dried to obtain a grayish CuSO ₄ powder close to white color. The obtained CuSO ₄ 80wt% and Super P carbon black 20wt% were pulverized and mixed by a high energy ball mill process. The ball mill was carried out in a nitride ball and container for 15 hours at 500 rpm, and 30 balls were used. Accordingly, N-CuSO ₄ /C powder was obtained.

90wt% of the obtained powder and 10wt% of polyvinylidene fluoride were dissolved in N-methyl-2-pyrrolidone (NMP), an organic solvent, to prepare a slurry. The resulting slurry was applied to an Al foil with a uniform thickness using a doctor blade, and dried in an oven at 100° C. for 12 hours to prepare an N-CuSO ₄ /C positive electrode.

Anode Comparative Example

Except that which passes the high-nano particle formation process proceeds energy ball mill, and performs the same process as manufacturing the positive electrode active material obtained by examples for CuSO ₄ pristine powder to prepare a pristine cathode CuSO _4.

Secondary battery manufacturing example

Used as a positive electrode according to the positive electrode preparation example, in a glove box in an argon environment, metal sodium was used as a negative electrode, and a glass filter was used as a separator, 1M NaPF ₆ electrolyte and organic solvent EC; DMC:FEC (49: 49:2 vol.%) was used to prepare an R2032 type cell.

Comparative Example of Secondary Battery

A secondary battery was manufactured using the same method as the secondary battery manufacturing example, except that the pristine CuSO ₄ positive electrode according to the positive electrode comparative example was used instead of the N-CuSO ₄ /C positive electrode according to the positive electrode manufacturing example.

2 is a graph showing charge and discharge characteristics according to C-rate of a secondary battery manufactured according to a secondary battery manufacturing example. In particular, FIG. 3 is a graph showing charge/discharge characteristics of a secondary battery manufactured according to a secondary battery manufacturing example at a current charge/discharge rate C/50-rate. At this time, in a 30°C environment, charging was performed up to 4.1V, and discharge was performed up to 1.2V.

2 and 3, as charging and discharging are performed at various current charging/discharging rates from C/50-rate to 10C-rate. The average operating voltage of the secondary battery according to the secondary battery manufacturing example was 3V. Through this, it can be seen that the secondary battery according to the secondary battery manufacturing example can have an excellent energy density. In particular, it can be seen that when charging C/50-rate current, the charging capacity has a high capacity of 325mA/g, which reaches 91% compared to the theoretical capacity of 335mAh/g. In addition, in the case of 10C-rate current charging and discharging, it appears that the charging/discharging capacity of the secondary battery is maintained at 122mA/g, despite the rapid charging and discharging speed, and it can be confirmed that the charging rate characteristics are excellent even at high currents. I can. In addition, it can be seen that the secondary battery has a high coulomb efficiency of 99% or more.

4 is a graph showing charge/discharge capacity and Coulomb efficiency according to the number of cycles of a secondary battery manufactured according to a secondary battery manufacturing example.

In detail, the first cycle was conducted at a current charge/discharge rate of C/3-rate, and after that, the cycle was conducted at 1 C-rate to measure the result of charging and discharging for a total of 200 cycles. Referring to FIG. 4, the capacity after 200 cycles of charging and discharging at 1 C-rate was 127 mAg/g. This means that even when the number of charge/discharge cycles is 200, the capacity of 72% of the initial capacity is maintained, and it can be seen that the secondary battery according to the secondary battery manufacturing example of the present invention has an excellent capacity retention rate and excellent stability. .

5 is a graph showing charge/discharge characteristics according to C-rate of a secondary battery manufactured according to a secondary battery comparative example, and FIG. 6 is a graph showing charge and discharge capacity according to the number of cycles of a secondary battery manufactured according to the secondary battery manufacturing example. It is a graph.

As described above, the electrochemical properties of the secondary battery according to an embodiment of the present invention are excellent as the surface area of the particles increases as the powder used as the positive electrode active material undergoes a nanoparticle formation process by performing a milling process. It is considered to be. Accordingly, it is possible to provide a secondary battery having high capacity and high energy density characteristics.

Although described with reference to the above embodiments, those skilled in the art will understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention described in the following claims. I will be able to.

100: secondary battery
110: negative electrode current collector
120: negative active material layer
130: separator
140: positive active material layer
150: positive electrode current collector
160: electrolyte

Claims (12)

Pulverizing and mixing the active material for a secondary battery including sulfur oxyacid anion and a conductive material at a speed of 400 to 800 rpm using a high energy ball mill to prepare a nanoparticle-formed active material-conductive material composite powder;
Preparing a slurry by mixing the active material-conductive material composite powder and a binder; And
A method of manufacturing an electrode for a secondary battery comprising the step of applying and drying the slurry on a current collector. The method according to claim 1,
The method of manufacturing an electrode for a secondary battery including the active material for a secondary battery represented by the following Formula 1 as the active material for a secondary battery containing sulfur oxyacid anion:
[Formula 1]
M _a CuS _x O _y F _b
In Formula 1,
M is a Group 1 alkali metal,
x is an integer from 1 to 5,
y is an integer from 2 to 9,
a and b are each independently 0 or 1. The method according to claim 2,
The active material for a secondary battery represented by Formula 1 is a method of manufacturing an electrode for a secondary battery represented by Formula 2:
[Formula 2]
M _a CuS _x O _y
In Formula 1,
a is 0 or 1,
M is a Group 1 alkali metal,
x is an integer from 1 to 5,
y is an integer from 2 to 9. The method according to claim 2,
M in Formula 1 is lithium (Li) or sodium (Na), a method of manufacturing an electrode for a secondary battery. The method according to claim 1,
The sulfur oxygenate anions are SO ₃ ^2- (sulfite), SO ₄ ^2- (sulfate), SO ₃ ^2- (sulfite), S ₂ O ₃ ^2- (thiosulfate), S ₂ O ₄ ^2- (dithionite), S ₂ O ₅ ^2- (disulfite), S ₂ O ₆ ^2- (dithionate), S ₂ O ₇ ^2- (disulfate), S ₂ O ₈ ^2- (peroxydisulfate) or S ₄ O ₆ ^2- (tetrathionate) secondary Method of manufacturing an electrode for a battery.
delete delete delete delete delete The method according to claim 1,
The milling process is a method of manufacturing an electrode for a secondary battery to be carried out for 10 to 24 hours. delete

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