KR20110115025A - Anode materias coated by self-assembled insulating layer, lithium ion battery including the same and the fabrication methods thereof - Google Patents

Abstract

The present invention includes a current collector, a negative electrode active material on the current collector and an insulating layer on the negative electrode active material, the insulating layer comprises agglomerates formed by self-assembly of insulating nano-materials, in particular the aggregate is a spherical, doughnut type And it relates to a negative electrode for a secondary battery of at least one form selected from the group consisting of ellipses.
In addition, (a) forming a spray solution in which the insulating nano-material is dispersed, and (b) electrospraying the spray solution on the negative electrode active material on the current collector, to form an insulating layer including an aggregate It provides a method for producing a negative electrode for a secondary battery, and particularly a method for producing a negative electrode for a secondary battery, the aggregate is at least one form selected from the group consisting of spherical, doughnut and elliptical.

Description

Anode active material coated with self-assembled insulating layer, a secondary battery having the same, and a method for manufacturing the same

The present invention relates to a negative electrode active material coated with a self-assembled insulating layer, a secondary battery comprising the same, and a method of manufacturing the same.

A lithium ion secondary battery is generally composed of a negative electrode, a positive electrode, an electrolyte, and a separator. Safety is very important in the design of battery cells. It is very important to prevent rupture or ignition due to a short circuit between the cathode and the anode. The purpose of forming a separator (insulation sheet, separator) between the positive electrode and the negative electrode in the lithium ion secondary battery is to minimize heat generation and ignition that may occur due to a short circuit between the positive electrode and the negative electrode. However, when the separator shrinks or expands due to prolonged use of the secondary battery, a short circuit between the positive electrode and the negative electrode may occur.

Matsushida improved the stability of the battery by coating a heat resistance layer (HRL) made of ceramic material on the surface of the negative electrode to prevent abnormal heat generation due to a short circuit during use of the secondary battery (GTB2006121492, GTB2006121011). . LG Chem reported a secondary battery that improved stability by coating a ceramic heat resistance layer on both or one side of the separator to minimize shrinkage and expansion of the separator. In order to coat the ceramic particles used as the heat resistance layer in a large area, there is a method of coating a paste mixed with ceramic particles and a polymer binder by screen printing or by impregnating a solution in which ceramic particles are dispersed.

However, the above methods may be non-uniform coating thickness during the process, there is a technical difficulty in coating a very thin heat resistance layer uniformly on the electrode active material. In addition, since an additional drying process for drying the binder used is required, there is a problem in that the process cost increases.

The present invention has been made to solve the above problems, an object of the present invention is to provide a coating layer that serves as a heat resistance layer, by electrically spraying insulating nanoparticles dispersed in a solution uniformly without a binder on the negative electrode active material The nanoparticles are self-assembled to form agglomerate structures such as spherical, donut-shaped, and elliptical, to provide a coating layer and a method of manufacturing the same, which can prevent a short circuit between the cathode and the anode while maintaining the porous structure. Forming an insulating layer without the use of a binder does not require an additional drying process in the conventional method, and provides a structure that facilitates penetration of an electrolyte by forming a porous structure in the process of self-assembling nanoparticles.

The above problems include the current collector of the present invention, the negative electrode active material on the current collector and the insulating layer on the negative electrode active material, wherein the insulating layer includes aggregates formed by self-assembly of insulating nanomaterials, particularly aggregates. It is solved by a negative electrode for a secondary battery which is at least one form selected from the group consisting of spherical, donut-shaped and elliptical.

In addition, (a) forming a spray solution in which the insulating nanomaterial is dispersed; And (b) electrospraying the spray solution on the negative electrode active material on the current collector to form an insulating layer including an aggregate, and particularly, the aggregate is spherical, donut-shaped, and elliptical. It is solved by a method of manufacturing a negative electrode for a secondary battery which is at least one form selected from the group consisting of.

According to the present invention, insulating nanomaterials having excellent insulating properties are self-assembled to form an aggregate. Since the aggregate is agglomerated in a spherical shape, a donut shape, an oval shape, and the like of various sizes, the insulating layer is formed. Excellent insulation but pore structure is well developed. In addition, while being coated on the surface layer of the carbon-based negative electrode active material, it provides a negative electrode having excellent thermal stability and a secondary battery comprising such a negative electrode. In addition, to provide a method for manufacturing a negative electrode and a secondary battery.

According to the present invention, by spraying a solution in which the insulating nanomaterials are uniformly dispersed to form agglomerates, the porous structure is better formed than the insulating coating layer obtained by the prior art (screen printing method or impregnation method), thereby infiltrating the electrolyte. It can be made easily and excellent in electrochemical properties, it can provide a secondary battery having a very high thermal safety.

In addition, it is possible to provide a uniform coating layer in which the thickness is maintained at a constant thickness, and since the polymer binder is not used, there is no deterioration of the electron and ion conduction characteristics caused by the binder, and an additional drying process for removing the binder is unnecessary. To provide.

1 is a scanning electron micrograph (x 10,000) of a negative electrode active material in which 95% by mass of graphite and 5% by mass of carbon black are mixed.
FIG. 2 is a scanning electron micrograph (x 10,000) of a negative electrode active material obtained by electrospraying 1.000 μl of a dispersion solution in which 1 mass% Al ₂ O ₃ nanopowder was dispersed in ethanol according to an embodiment of the present invention.
3 is a scanning electron micrograph (x 10,000) of a negative electrode active material obtained by electrospraying 10.000 μl of a spray solution in which 1% by mass of Al ₂ O ₃ nanopowder is dispersed in ethanol according to an embodiment of the present invention.
4 is a scanning electron micrograph (x 10,000) of an anode active material obtained by electrospraying 3.000 μl of a spray solution in which 0.5 mass% Al ₂ O ₃ nanopowder is dispersed according to an embodiment of the present invention.
5 is a scanning electron micrograph (x 10,000) of a negative electrode active material obtained by electrospraying a mixed solution of alumina dispersion (aluminum oxide, dispersion) and ethanol (mixing ratio 2: 8) according to an embodiment of the present invention.
FIG. 6 is a scanning electron micrograph (x 10,000) of an anode active material obtained by electrospraying an alumina dispersion (aluminum oxide, dispersion) and an ethanol mixed solution (mixing ratio 3: 7) according to an embodiment of the present invention.
FIG. 7 is a scanning electron micrograph (x 10,000) of an anode active material obtained by electrospraying an alumina dispersion (aluminum oxide, dispersion) and an ethanol mixed solution (mixing ratio of 5: 5) according to an embodiment of the present invention.
FIG. 8 is a scanning electron micrograph (x 10,000) of an anode active material obtained by electrospraying an alumina dispersion (aluminum oxide, dispersion) and an ethanol mixed solution (mixing ratio 1: 9) according to an embodiment of the present invention.
FIG. 9 is an enlarged scanning electron micrograph (x 200,000) of FIG.
10 is a scanning electron micrograph (x 10,000) of TiO ₂ nanopowder aggregates prepared according to an embodiment of the present invention.
FIG. 11 shows an enlarged scanning electron micrograph (x 40,000) of spherical, donut shaped, elliptical shaped TiO ₂ nanopowder aggregates prepared according to an embodiment of the present invention.
12 is a cross-sectional scanning electron micrograph (x 5,000) of an insulating layer comprising TiO ₂ nanopowder aggregates prepared according to an embodiment of the present invention.

The negative electrode for a secondary battery of the present invention includes a current collector, a negative electrode active material on the current collector, and an insulating layer on the negative electrode active material, wherein the insulating layer includes aggregates in which insulating nanomaterials are self-assembled. That is, the carbon-based negative electrode active material is coated on the current collector, and the upper layer includes an insulator layer formed by coating nanomaterial aggregates having excellent electrical insulation through self-assembly. Aggregates formed during the self-assembly process may be made of insulating nano-materials are entangled in various forms, such as spherical, donut-shaped, oval. The size of the aggregate can be from 100 nm to 5 μm, and the size of the aggregate can be evaluated by the longest distance on the cross section, that is, the diameter of the sphere, the length of the major axis of the ellipse, and the like.

Between the aggregates, pores of 10 nm to 10 μm may be formed. These pores facilitate the penetration of the electrolyte and provide high rates suitable for secondary batteries.

The thickness of the insulating layer may be 0.5 μm to 20 μm.

The insulating nanomaterial may be a material having little reactivity with lithium. Specifically, Al ₂ O ₃ , ZrO ₂ , MgO, Ta ₂ O ₅ , CeO ₂ , SiO ₂ , Y ₂ O ₃ , BaTiO ₃ , SrTiO ₃ And HfO ₂ And the like. The insulating nanomaterial may be a material having a relatively low reactivity with lithium. Specifically, TiO ₂ and Fe ₂ O ₃ may be used. In addition, the insulating nanomaterial may be Li ₄ Ti ₅ O ₁₂ , which is relatively reactive with lithium.

The negative electrode active material may be at least one selected from the group consisting of graphite-based materials, multi-walled carbon nanotubes, single-walled carbon nanotubes, and double-walled carbon nanotubes.

In order to improve the conductive properties of the negative electrode active material formed on the current collector may further include at least one carbon particles selected from the group consisting of super P, Ketjenblack and denca black. Such carbon particles may be coated on the surface of the graphite material (eg, graphite), or may be distributed between the carbon nanotubes.

On the other hand, the secondary battery may be formed by including the negative electrode, the positive electrode, the electrolyte, and the separator according to the present invention as described above.

In the method of manufacturing a negative electrode for a secondary battery of the present invention, basically, (a) forming an injection solution in which insulating nanomaterials are dispersed, and (b) electrospraying the injection solution on the negative electrode active material on the current collector, and aggregates. Forming an insulating layer comprising a. The aggregate may be in at least one form selected from the group consisting of spherical, donut and elliptical.

As a pretreatment, (a ') may further include microbead milling the insulating nanomaterial. This is to improve the dispersibility of the insulating nanomaterial in the spray solution.

As a post-treatment, the method may further include drying the insulating layer, and may further include thermocompressing the insulating layer between the steps (b) and (c). In the case of the thermocompression step, some of the spherical, donut-shaped, or elliptical aggregates may be flatly crushed according to the compressive strength.

The aggregates may have a size of 100 nm to 5 μm, pores of 10 nm to 10 μm may be formed between the aggregates, and the thickness of the insulating layer may be 0.5 μm to 20 μm.

In the method of manufacturing a negative electrode for a secondary battery of the present invention, the insulating nanomaterial is Al ₂ O ₃ , ZrO ₂ , MgO, Ta ₂ O ₅ , CeO ₂ , SiO ₂ , Y ₂ O ₃ , BaTiO ₃ , SrTiO ₃ And at least one selected from the group consisting of HfO ₂ , at least one selected from the group consisting of TiO ₂ and Fe ₂ O ₃ , or Li ₄ Ti ₅ O ₁₂ , and the negative electrode active material is a graphite-based material and multi-walled carbon nanotubes. , At least one selected from the group consisting of single-walled carbon nanotubes and double-walled carbon nanotubes, and at least one selected from the group consisting of super P, ketjen black, and denca black for improving electrical conductivity of the negative electrode active material. It may further include carbon particles.

The concentration of the insulating nanomaterial of the spray solution of step (a) may be 0.5 to 20% by mass relative to the solvent, and the solvent of the spray solution of step (a) may be ethanol, methanol, propanol, butanol, isopropyl alcohol, dimethylform. Any one or a mixture of two or more selected from the group consisting of amide (DMF), acetone, detrahydrofuran, toluene and water can be used. However, the present invention is not limited thereto.

The size and distribution of the aggregates constituting the insulator coating layer vary depending on the type of the solvent used in the dispersion solution of step (a) and the concentration of the insulating nanomaterial. Specifically, when volatile ethanol is used, the nanoparticles are injected at the tip of the injection and the volatilization of the solvent is carried out, so that the charged particles are spherical, donut-shaped, elliptical-shaped nanoparticle aggregates to minimize the surface area. It will be formed into fields. On the other hand, when using less volatile water as a solvent, the solvent is not volatilized well until the nanoparticles are coated on the surface of the negative electrode active material (current collector) after spraying from the tip, and the negative electrode active material coated on the current collector Since nanoparticles are coated on the surface and volatilization of water occurs, uniform aggregates are not easily formed, and coating is performed on the negative electrode active material layer in the form of a non-uniform thin layer.

The electrospray of step (b) can be achieved by applying a voltage of 5 to 30 kV. At the time of electrospraying in step (b), the shape of the agglomerate may also change depending on the hole size and the ejection speed of the needle from which the injection solution is ejected. If the discharge rate is too fast, the spherical aggregates are hardly formed.

Drying of step (c) may be in the range of 50 to 400 ° C.

In order to improve the dispersibility of the insulating nanomaterial in the spray solution of step (a), a dispersant, a surfactant, etc. may be further included in the spray solution.

Dispersants include polyvinylacetate, polyurethane, polyetherurethane, polyurethane copolymer, cellulose acetate, cellulose derivative, polymethylmethacrylate (PMMA), polymethylacrylate (PMA), polyacrylic copolymer, polyvinylacetate Copolymer, Polyvinyl Alcohol (PVA), Polyfuryl Alcohol (PPFA), Polystyrene (PS), Polystyrene Copolymer, Polyethylene Oxide (PEO), Polypropylene Oxide (PPO), Polyethylene Oxide Copolymer, Polypropylene Oxide Copolymer At least one selected from the group consisting of polycarbonate (PC), polyvinylchloride (PVC), polycaprolactone, polyvinylpyrrolidone (PVP), polyvinyl fluoride, polyvinylidene fluoride copolymer and polyamide Either one can be used.

As the surfactant, at least one selected from the group consisting of Triton X-100, acetic acid, cetyltrimethyl ammonium bromide (CTAB), isopropyltris titanate, and 3-aminopropyltriethoxy-silane can be used.

Meanwhile, a secondary battery may be manufactured by adding a cathode, an electrolyte, and a separator using the anode manufactured according to the present invention as described above.

Example

Hereinafter, a method of manufacturing a negative electrode having a negative electrode active material coated with an aggregate of insulating nanomaterials aggregated through a self-assembly process according to the present invention will be described in detail with reference to the accompanying drawings. However, this is only an example for clarity and the present invention is not limited thereto.

Example 1 Preparation of Insulation Layer by Electrospray of Spray Solution Disperse 1% by Mass of Alumina Nanoparticles

0.1 g of aluminum oxide (alumina) nanoparticles (Aluminum Oxide Nanopower, <50 nm, Aldrich) were uniformly dispersed in 10 g of ethanol to prepare a 1% by mass suspension of aluminum oxide. In general, in the case of nanoparticles, aggregation of particles frequently occurs. This aggregation of particles makes it difficult to maintain a uniform dispersion in the solvent. In this case, since stable electrospray is difficult to proceed, microbead milling using aluminum oxide beads having a size of 0.015 mm-0.05 mm was performed in this embodiment. As a result, an aluminum oxide dispersion solution having excellent dispersibility could be prepared. The content of the insulating particles present in the solvent for the stable spraying is set in the range of 0.2-20 mass%. The prepared dispersion was electrosprayed at room temperature directly on the current collector coated with the negative electrode active material.

The electric spray device used in the experiment is as follows. The electric spray device is composed of a spray nozzle, a high voltage generator, a grounded conductive substrate, and the like connected to a metering pump capable of quantitatively dispersing the dispersion. A current collector coated with a negative electrode active material is placed on a grounded conductive substrate, and a grounded conductive substrate is used as a cathode, and a spray nozzle with a pump with a controlled discharge amount per hour is used as a cathode. A voltage of 8-30 kV is applied, and the solution discharge rate is adjusted to 10-300 µl / min and sprayed on the current collector until the thickness of the thin layer becomes 0.5-10 µm. In order to increase the stability of the battery, the spraying time may be increased to increase the thickness of the insulating coating layer to 20 μm.

FIG. 1 is for comparison, and is a surface scanning microscope photograph of a thin layer coated on an aluminum current collector by mixing a commercially available graphite-based negative electrode active material (95% by mass) and carbon black (5% by mass). The graphite particles have a size of 5-10 μm, and fine carbon particles having a size of 10-20 nm are coated on the surface of the graphite particles.

In Example 1, the prepared spray solution was transferred to a syringe, mounted on an electrospray apparatus, and applied a thin layer of insulator by applying a voltage between the tip of the syringe and the lower substrate. The voltage was 16 kV, the flow rate was 40 μl / min and the distance between the tip and the substrate was 12 cm. The total discharge amount was 1,000 μl, and a small amount was discharged to observe the microstructure. FIG. 2 is a scanning electron micrograph (x10,000) of a thin layer of an anode active material coated with the aluminum oxide aggregate obtained by electrospraying as described above.

As shown in FIG. 2, large spherical aluminum oxide aggregates of 400 nm-4 μm are uniformly coated on the surface of the graphite-based negative electrode active material.

3 is a scanning electron micrograph (x 10,000) obtained after electrospraying by increasing the discharge amount to 10,000 μl. Even if the discharge amount is increased from 1,000 μl (FIG. 2) to 10,000 μl (FIG. 3), it can be confirmed that spherical or elliptical aluminum oxide aggregates having different sizes are coated. In particular, referring to the part indicated by a small circle, it can be confirmed that the size of the aggregate is wide from 200 nm to 4 μm. The result shows that the thickness of the insulating layer coated on the negative electrode active material layer can be easily adjusted through the adjustment of the discharge amount without a great difference in the shape of the aggregated particles.

Example 2 Preparation of Insulation Layer by Electrospray of Spray Solution Dispersed 0.5% by Mass of Alumina Nanoparticles

Electrospray was carried out under similar conditions as in Example 1, but the experiment was carried out using an electrospray solution having a concentration of 0.5% by mass in the ethanol solvent of the used aluminum oxide nanoparticles. The voltage was 16 kV, the flow rate was 40 µl / min, the distance between the tip and the substrate was 12 cm, and the discharge amount was 3,000 µl.

4 is a scanning electron micrograph (x10,000) of a thin layer of the negative electrode active material coated with the aluminum oxide aggregate obtained by electrospraying as described above. Referring to the portion indicated by the small circle in Figure 4, it can be seen that the spherical or elliptical aggregate is well coated. In particular, when the thin layer was obtained using a 1% by mass aluminum oxide dispersion solution (Fig. 2) it is confirmed that the aggregate size (200 nm-900 nm) is significantly smaller, the coating uniformity is higher.

Example 3 Preparation of Insulation Layer by Electrospray of Spray Solution Dispersed 0.5% by Mass of Alumina Nanoparticles in Water and Ethanol Mixture

Electrospray was carried out under similar conditions as in Example 1, but the experiment was performed by varying the solvent of the aluminum oxide nanoparticle dispersion solution.

An aqueous solution of aluminum oxide (Aluminum oxide, dispersion, a solution in which 10% by mass of aluminum oxide (<50 nm) was dispersed in a H ₂ O solvent) was mixed with ethanol to prepare a spray solution (curing solution).

The aluminum oxide aqueous solution and ethanol were mixed so that they were 2: 8, 3: 7, 5: 5 by mass ratio, and electrospraying was carried out, respectively. At this time, the voltage was 16 kV, the flow rate) was 40 µl / min, the distance between the tip and the substrate was 12 cm, and the discharge amount was 3,000 µl.

5, 6, and 7 are a scan of a thin layer of an anode active material coated with an aluminum oxide aggregate obtained by electrospraying a spray solution in which a ratio of an aqueous aluminum oxide solution and ethanol is 2: 8, 3: 7, and 5: 5, respectively. An electron microscope (x10,000) photograph.

In the case of using a 2: 8 ratio of aluminum oxide dispersion having a high ethanol content, it is observed that aggregates of fine particles are uniformly applied, and application by some fine nanoparticles is also observed. In the case of using a spray solution having a ratio of 5: 5 having a relatively high water content, the coating by the fine nanoparticles as well as the spherical aggregates are also observed over a wide range as shown in FIG. 7. In the case of using a spray solution with a 3: 7 ratio, the shape of the agglomerates corresponding to the median size and distribution of the results using the spinner with a ratio of 2: 8 and 5: 5 was shown.

Example 4 Preparation of Insulation Layer by Low-speed Electrospray of a Spray Solution Dispersed 0.5% by Mass of Alumina Nanoparticles in Water and Ethanol Solvent

Electrospraying was carried out similarly to Example 3, but the injection solution was prepared by mixing the ratio of the aluminum oxide solution and ethanol in a ratio of 1: 9, and electrospraying 8,000 μl at a discharge rate of 15 μl / min. Insulator thin layers were prepared.

Referring to FIG. 8, it can be seen that the spherical particles are well developed to form a thin layer of aluminum oxide aggregate. Referring to FIG. 9, in which the aggregate of a portion indicated by a small circle is enlarged, the aggregates are fine at 50 nm. It can be seen that it is composed of aluminum oxide nanoparticles. Since aluminum oxide is a material having excellent insulation properties, the surface of the graphite-based negative electrode active material is uniformly coated, thereby minimizing explosion due to a short circuit between the negative electrode and the positive electrode, thereby forming a secondary battery having high stability.

Since the 50 nm sized particles form a 200 nm-5 μm sized aggregate with a larger size to form an insulator thin layer, large pores between the aggregates are formed. Penetration of the electrolyte can easily occur through these pores, resulting in an insulating layer structure suitable for secondary batteries requiring high rate characteristics.

In addition, since the injector solution used in the present invention has no insulator and a thin insulator is formed, there is an advantage that the interference of ions and electrons by the binder is very small.

Example 5 Preparation of Insulation Layer by Low Speed Electrospray of Spray Solution Dispersed 10 Mass% of Titanium Oxide Nanoparticles in Ethanol Solvent

Under the same conditions as the above examples, 1 g of titanium oxide nanoparticles (TiO ₂ Nanopower, <20 nm, Aldrich) was uniformly dispersed in 10 g of ethanol to prepare a 10% by mass suspension of aluminum oxide. In order to further improve the dispersion characteristics of the titanium oxide nanopowder, a dispersion solution was prepared through microbead milling (zirconia ball size: 0.05 mm). The prepared titanium oxide dispersion was electrosprayed at room temperature directly on the current collector coated with the negative electrode active material.

Referring to Figure 10, it can be seen that spherical or donut-shaped, elliptical aggregates are well developed to form a thin titanium oxide layer. As aggregates having various sizes (100 nm-2 μm) are formed, pores between the aggregates are well formed.

By uniformly coating the surface of the graphite-based negative electrode active material, it is possible to configure a secondary battery having high stability by minimizing explosion due to a short circuit between the negative electrode and the positive electrode. TiO ₂ is a material excellent in insulating properties. In addition, there is a reaction with Li, it is reported to show the theoretical capacity characteristics of 165 mAh / g. Therefore, by coating on the surface of the graphite-based material used as the negative electrode active material, it may have the function of the negative electrode active material as well as the role of the insulating layer itself. Iron oxides (Fe ₂ O ₃ , Fe ₃ O ₄ ) and Li ₄ Ti ₅ O ₁₂ have excellent explosion stability and simultaneously have insulating properties.

Penetration of the electrolyte used in the lithium secondary battery by the macropores between the aggregates because the TiO ₂ primary particles having a size of 20 nm form an aggregate having a size of 100 nm-2 μm with a larger size to form an insulator thin layer. Can easily occur, and may have an insulating layer structure suitable for a secondary battery requiring high rate characteristics.

FIG. 11 is an enlarged scanning electron microscope (x 40,000) photograph of FIG. 10. It can be seen that a relatively large donut-shaped TiO ₂ aggregate and spherical, elliptical TiO ₂ nanopowder aggregates were formed. Looking at Figure 11, it can be seen that the aggregate is composed of a combination of fine nanoparticles.

12 is a cross-sectional scanning electron micrograph of a thin layer of titanium oxide aggregate. It can be seen that the dense aggregated secondary aggregates are well formed in the thin layer.

Claims (30)

House,
A negative electrode active material on the current collector and
An insulating layer on the anode active material,
The insulating layer is a negative electrode for a secondary battery that includes agglomerates formed by self-assembled insulating nano-materials. The method of claim 1,
The aggregate is a negative electrode for a secondary battery, characterized in that at least one form selected from the group consisting of spherical, doughnut and elliptical. The method of claim 1,
The size of the aggregate is a negative electrode for secondary batteries, characterized in that 100nm to 5㎛. The method of claim 1,
A secondary battery negative electrode, characterized in that the pores of 10 nm to 10 ㎛ are formed between the aggregates. The method of claim 1,
The thickness of the insulating layer is a negative electrode for secondary batteries, characterized in that 0.5 to 20 ㎛. The method of claim 1,
The insulating nanomaterial is at least one selected from the group consisting of Al ₂ O ₃ , ZrO ₂ , MgO, Ta ₂ O ₅ , CeO ₂ , SiO ₂ , Y ₂ O ₃ , BaTiO ₃ , SrTiO ₃ and HfO ₂ . A secondary battery negative electrode made of. The method of claim 1,
The insulating nanomaterial is at least one selected from the group consisting of TiO ₂ and Fe ₂ O ₃ negative electrode for a secondary battery. The method of claim 1,
The insulating nanomaterial is Li ₄ Ti ₅ O _{12 The} negative electrode for a secondary battery, characterized in that. The method of claim 1,
The negative electrode active material is at least one selected from the group consisting of graphite-based materials, multi-walled carbon nanotubes, single-walled carbon nanotubes and double-walled carbon nanotubes. 10. The method of claim 9,
The negative electrode active material negative electrode further comprises at least any one carbon particles selected from the group consisting of super P, Ketjen black and denka black. A secondary battery comprising the negative electrode, the positive electrode, the electrolyte and the separator according to any one of claims 1 to 10. (a) forming a spray solution in which the insulating nanomaterial is dispersed; And
(B) a method of manufacturing a negative electrode for a secondary battery comprising the step of electrospraying the injection solution on the negative electrode active material on the current collector, to form an insulating layer including an aggregate. The method of claim 12,
The aggregate is a method of manufacturing a negative electrode for a secondary battery, characterized in that at least one form selected from the group consisting of spherical, doughnut and elliptical. The method of claim 12, wherein before step (a),
(A ') The method of manufacturing a negative electrode for a secondary battery, further comprising the step of microbead milling the insulating nanomaterial. The method of claim 12, wherein after step (b):
(c) a method of manufacturing a negative electrode for a secondary battery, further comprising the step of drying the insulating layer. The process of claim 15, wherein between step (b) and step (c):
The method of manufacturing a negative electrode for a secondary battery, further comprising the step of thermally compressing the insulating layer. The method of claim 12,
The size of the aggregate is a manufacturing method of the negative electrode for secondary batteries, characterized in that 100nm to 5㎛. The method of claim 12,
A method of manufacturing a negative electrode for a secondary battery, characterized in that pores of 10 nm to 10 μm are formed between the aggregates. The method of claim 12,
The thickness of the insulating layer is 0.5 ㎛ to 20 ㎛ manufacturing method of the negative electrode for a secondary battery, characterized in that. The method of claim 12,
The insulating nanomaterial is Al ₂ O ₃ , ZrO ₂ , MgO, Ta ₂ O ₅ , CeO ₂ , SiO ₂ , Y ₂ O ₃ , BaTiO ₃ , SrTiO ₃ , HfO ₂ , TiO ₂ , Fe ₂ O ₃ and Li ₄ Method for producing a negative electrode for a secondary battery, characterized in that at least one selected from the group consisting of Ti ₅ O ₁₂ . The method of claim 12,
The negative electrode active material is at least one selected from the group consisting of graphite-based material, multi-walled carbon nanotubes, single-walled carbon nanotubes and double-walled carbon nanotubes, the method of manufacturing a negative electrode for a secondary battery. The method of claim 21,
The negative electrode active material may further include at least one carbon particle selected from the group consisting of super P, Ketjen black, and denka black. The method of claim 12,
Method for producing a negative electrode for a secondary battery, characterized in that the concentration of the insulating nano-material present in the injection solution of step (a) is 0.5 to 20% by mass. The method of claim 12,
The solvent of the spray solution of step (a) is any one or a mixture of two or more selected from the group consisting of ethanol, methanol, propanol, butanol, isopropyl alcohol, dimethylformamide (DMF), acetone, detrahydrofuran, toluene and water. Method for producing a negative electrode for a secondary battery, characterized in that. The method of claim 12,
Electrospray of step (b) is a method of manufacturing a negative electrode for a secondary battery, characterized in that by applying a voltage of 5 to 30 kV. 16. The method of claim 15,
Drying of step (c) is a method for producing a negative electrode for a secondary battery, characterized in that made in the range of 50 to 400 ℃. The method of claim 12,
The injection solution of step (a) further comprises a dispersing agent, a surfactant or a mixture thereof. The method of claim 27,
The dispersant is polyvinyl acetate, polyurethane, polyetherurethane, polyurethane copolymer, cellulose acetate, cellulose derivative, polymethylmethacrylate (PMMA), polymethylacrylate (PMA), polyacrylic copolymer, polyvinylacetate Copolymer, Polyvinyl Alcohol (PVA), Polyfuryl Alcohol (PPFA), Polystyrene (PS), Polystyrene Copolymer, Polyethylene Oxide (PEO), Polypropylene Oxide (PPO), Polyethylene Oxide Copolymer, Polypropylene Oxide Copolymer At least one selected from the group consisting of polycarbonate (PC), polyvinylchloride (PVC), polycaprolactone, polyvinylpyrrolidone (PVP), polyvinyl fluoride, polyvinylidene fluoride copolymer and polyamide Method for producing a negative electrode for a secondary battery, characterized in that any one. The method of claim 27,
The surfactant is at least one selected from the group consisting of Triton X-100, acetic acid, cetyltrimethyl ammonium bromide (CTAB), isopropyltris titanate and 3-aminopropyltriethoxy-silane Method for producing a negative electrode for a battery. 30. A method of manufacturing a secondary battery, comprising manufacturing a negative electrode by the method of any one of claims 12 to 29, and forming a positive electrode, an electrolyte, and a separator.

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