WO2018124448A1

WO2018124448A1 - Anode composition for lithium secondary battery, method for preparing same, and lithium secondary battery comprising same

Info

Publication number: WO2018124448A1
Application number: PCT/KR2017/012229
Authority: WO
Inventors: 조재필; 마지영; 성재경
Original assignee: 울산과학기술원
Priority date: 2016-12-30
Filing date: 2017-11-01
Publication date: 2018-07-05
Also published as: KR101908603B1; KR20180078889A

Abstract

The present invention provides an anode composition for a lithium secondary battery, which comprises: a core; and a shell disposed on the surface of the core and having at least one active material layer and at least one non-active material layer alternately laminated thereon, wherein the at least one active material layer changes in volume upon reaction with lithium ions and the at least one non-active material layer is smaller in volume change rate than the at least one active material layer.

Description

Anode composition for lithium secondary battery, preparation method thereof and lithium secondary battery comprising same

Embodiments of the present invention relate to a negative electrode composition for a lithium secondary battery, a method for manufacturing the same, and a lithium secondary battery including the same. More particularly, a negative electrode composition for a lithium secondary battery for realizing a high capacity negative electrode having an improved lifetime, and a method for manufacturing the same. It relates to a lithium secondary battery comprising the same.

Mobile electronic communication devices have been rapidly developed through miniaturization, light weight, and high performance, and lithium secondary batteries that are easy to use are mainly used as power sources for these electronic devices. Therefore, in order to emphasize the mobile characteristics of the electronic communication device, it is necessary to develop a high capacity lithium secondary battery with high energy density. Lithium secondary batteries, which operate by repeatedly charging and discharging through insertion and desorption of lithium ions, are expected to be used not only as portable electronic devices such as mobile phones and laptops, but also as power supplies for medium and large devices such as electric vehicles and energy storage devices. do.

One of the important factors that influence the performance improvement of such a lithium secondary battery is the quality of the negative electrode material. Among them, the focus is on increasing the charge / discharge capacity of lithium ions per unit volume through development of a negative electrode material, that is, developing a high capacity lithium secondary battery having a high energy density. Currently, carbon-based is mainly used as a negative electrode active material of a lithium secondary battery. However, since the upper limit of the theoretical electric capacity of graphite, which is a representative carbon-based negative electrode material, is limited to about 372 mAh / g, it is necessary to apply a new high-capacity negative electrode material to develop a high capacity lithium secondary battery.

As a result, many researchers are turning to silicon-based anode materials with large lithium capacities. The theoretical capacitance of silicon-based anode materials is 4200mAh / g, more than 10 times that of graphite, increasing the likelihood of becoming a next-generation cathode material in place of graphite.

However, silicon has poor cycle characteristics compared to the carbon-based negative electrode active material, which makes it an obstacle to practical use. The reason is that about 400% of volume change occurs during the charging and discharging process, that is, the charging and dissociation of silicon with lithium ions, and the mechanical stress caused by this is applied to the inside and the surface of the silicon anode. This is because cracking occurs. When the charge and discharge cycles are repeated, the silicon negative electrode active material is detached from the current collector, and electrical insulation may occur due to the cracks generated in the silicon negative electrode active material, thereby causing a problem in that the battery life is drastically reduced.

The present invention is to solve various problems including the above problems, and to provide a negative electrode composition for a lithium secondary battery, a method of manufacturing the same and a lithium secondary battery comprising the same for implementing a high capacity negative electrode with improved lifetime. do. However, these problems are exemplary, and the scope of the present invention is not limited thereby.

Embodiments of the present invention to provide a negative electrode composition for a lithium secondary battery, a method of manufacturing the same and a lithium secondary battery comprising the same.

According to an aspect of the present invention, at least one active material layer disposed on the core and the surface of the core and reacting with lithium ions to generate a volume change, and at least one having a smaller volume change rate than the at least one active material layer Provided is a negative electrode composition for a lithium secondary battery having a shell in which an inactive material layer is alternately laminated.

According to one embodiment of the present invention made as described above, it is possible to minimize the volume expansion of the high capacity negative electrode active material to improve the life characteristics of the lithium secondary battery comprising the same.

In addition, the manufacturing cost can be reduced to contribute to mass production of a high capacity negative electrode active material.

Of course, the scope of the present invention is not limited by these effects.

1 is a process diagram sequentially showing the manufacturing process of the negative electrode composition for a lithium secondary battery according to an embodiment of the present invention.

2 is a cross-sectional view schematically showing a negative electrode composition for a rechargeable lithium battery according to another embodiment of the present invention.

3 is a cross-sectional view schematically showing a negative electrode composition for a rechargeable lithium battery according to another embodiment of the present invention.

4 is a TEM photograph of a negative electrode composition for a rechargeable lithium battery according to one embodiment of the present invention.

5 is an enlarged TEM photograph of part A of FIG. 4.

6 is a graph showing a change in discharge capacity according to the number of cycles of a lithium secondary battery according to an embodiment and a comparative example of the present invention.

7 is a graph showing a change in coulombic efficiency according to the number of cycles of a lithium secondary battery according to an embodiment and a comparative example of the present invention.

8 is an exploded perspective view of a rechargeable lithium battery according to one embodiment of the present invention.

It is disposed on the shell, it may further include a conductive layer containing carbon.

The core may comprise Si.

The at least one active material layer may include Si.

The at least one inert material layer may include at least one of SiO ₂ , Al ₂ O ₃ , TiO ₂ , Fe ₃ O ₄ , soft carbon, hard carbon, and a polymer.

The lowermost layer of the shell may include at least one of SiO ₂ , Al ₂ O ₃ , TiO ₂ , Fe ₃ O ₄ , soft carbon, hard carbon, and a polymer.

The core has a spherical shape, and the shell may be arranged to surround at least a portion of the core.

The core may have a hollow spherical shape.

Each of the at least one active material layer and the at least one inert material layer may have a thickness of 1 to 200 nm.

The core may have a diameter of 1 to 500 nm.

The core may include Si, the at least one active material layer may include Si, the at least one inert material layer may include SiO ₂ , and the lowermost layer of the shell may include SiO ₂ .

According to another aspect of the invention, (a) forming a core comprising a first negative electrode active material nanoparticles, (b) forming a temporary active material layer containing a second negative electrode active material nanoparticles on the surface of the core Thereafter, heat treating the temporary active material layer in an air atmosphere to form an inactive material layer, (c) forming an active material layer including third negative active material nanoparticles on the inactive material layer, and (d) Provided is a method for producing a negative electrode composition for a lithium secondary battery, comprising; step b) and performing the step (c) by repeating a plurality of times in sequence.

(e) after step (d), may further comprise the step of forming a conductive layer containing carbon.

The first negative electrode active material nanoparticles are Si, and the Si may be formed by decomposing silane gas.

The second negative electrode active material nanoparticles may be Si, the Si may be formed by decomposing silane gas, and the inactive material layer may include SiO ₂ .

The third negative electrode active material nanoparticles are Si, and the Si may be formed by decomposing silane gas.

The core may be formed to have a spherical shape, and the active material layer and the inactive material layer may be formed to surround at least a portion of the core.

The core may be formed to have a hollow spherical shape.

Each of the active material layer and the inert material layer may have a thickness of 1 to 200 nm.

The core may have a diameter of 1 to 500 nm.

According to another aspect of the present invention, there is provided a lithium secondary battery having a cathode including an anode, an electrolyte, and a cathode composition for a lithium secondary battery according to any one of claims 1 to 10.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all transformations, equivalents, and substitutes included in the spirit and scope of the present invention. In the following description of the present invention, if it is determined that the detailed description of the related known technology may obscure the gist of the present invention, the detailed description thereof will be omitted.

The terms first, second, etc. used herein may be used to describe various components, but the components should not be limited by the terms. The terms are only used to distinguish one component from another.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings, and in the following description with reference to the drawings, substantially identical or corresponding components are given the same reference numbers, and redundant description thereof will be omitted. do. In the drawings, the thickness of layers, films, panels, regions, etc., are exaggerated for clarity. In the drawings, the thicknesses of layers and regions are exaggerated for clarity.

Referring to Figure 1, in order to manufacture a negative electrode composition 1 for a lithium secondary battery according to an embodiment of the present invention is subjected to the following processes.

First, (a) the core 10 is formed. In this case, the core 10 is formed to include the first negative electrode active material nanoparticles. The first negative electrode active material nanoparticles may be formed of various materials, for example, may include at least one of Si, Ge, Mg, Al, P, Ga, As, Cd, Au, and Bi.

In one embodiment, the first negative electrode active material nanoparticles may be Si. The Si nanoparticles may be formed by decomposing silane gas. Specifically, Si nanoparticles may be obtained by introducing silane gas and a carrier gas into the reactor and decomposing the silane gas in the reactor. In this case, the size of the Si nanoparticles may be adjusted by changing the mixing ratio of the silane gas and the carrier gas. As the carrier gas, H ₂ , N ₂ , Ar, HCl, Cl _2, etc. may be used, and a reaction temperature for decomposing the silane gas may be 500 to 1200 ° C., preferably 450 to 500 ° C., and the type of the silane gas It may be set to an appropriate temperature depending on the deposition conditions.

The core 10 may be formed using the Si nanoparticles generated as described above, but the core 10 may be formed to have a spherical shape as shown in FIG. 1, but is not limited thereto. no. That is, the shape of the wire and the tube, as well as may be formed in the form of a flat plate. Hereinafter, for convenience of description, the core 10 will be described in detail with reference to a case having a spherical shape.

The core 10 may be formed to have a diameter of 1 to 500 nm, preferably 5 to 100 nm. As such, by forming the core 10 small to have a diameter of several hundred nm or less, crack generation due to volume expansion of Si may be partially reduced when the core 10 is used as a negative electrode active material of a lithium secondary battery.

On the other hand, the Si nanoparticles in the step (a) has been described as being formed by supplying the silane gas, in addition, it is also possible to form the commercialized Si particles by mechanical grinding through ball milling or the like.

Next, (b) a step of forming the inert material layer 21i on the surface of the core 10. The step (b) may be subdivided into two steps. The first step is to form a temporary active material layer on the surface of the core 10, and the second step is to heat-treat the temporary active material layer in an atmospheric atmosphere. Step.

In the first step, the temporary active material layer formed on the surface of the core 10 is formed to include the second negative electrode active material nanoparticles. In this case, the second negative electrode active material nanoparticles may be formed of various materials, for example, may include at least one of Si, Ge, Mg, Al, P, Ga, As, Cd, Au, and Bi.

In one embodiment, the second negative electrode active material nanoparticles, like the first negative electrode active material nanoparticles of the previous step (a) may be Si. As described above, the Si nanoparticles may be formed by decomposing silane gas or by pulverizing commercially available Si particles by a method such as ball milling.

Thereafter, in the second step, the temporary active material layer is heat-treated in an air atmosphere to supply oxygen gas to the temporary active material layer. At this time, of course, the oxygen gas must be supplied in a state in which silane gas is blocked, and the temperature for heat treatment may be 750 to 950 degrees. As such, by adding oxygen to the temporary active material layer, the material included in the second negative electrode active material nanoparticles is changed into an oxide form to form the inactive material layer 21i. In the present embodiment, since the second negative electrode active material nanoparticles are formed of Si, the inactive material layer 21i is formed to include SiO ₂ .

As the inert material layer 21i is formed of SiO ₂ , durability of the spherical core 10 enclosed by the inert material layer 21i may be improved. In other words, SiO ₂ has a small volume change and not only disperses the Si nanoparticles properly, but also traps the Si nanoparticles in a small space to prevent the Si nanoparticles from being micronized and released due to the volume change. Therefore, it is possible to prevent electrical shorts due to micronization of Si nanoparticles, thereby improving cycle characteristics of the battery.

Meanwhile, the inert material layer 21i may include at least one of SiO ₂ , Al ₂ O ₃ , TiO ₂ , Fe ₃ O ₄ , soft carbon, hard carbon, and a polymer. The inert material layer 21i formed as described above is not directly involved in the redox reaction of the lithium secondary battery, but serves to mitigate volume expansion or side reaction of the first negative electrode active material included in the core 10. To this end, the material contained in the inactive material layer 21i may have a small volume change rate compared to the first negative electrode active material.

Next, (c) the active material layer 21 is formed on the inactive material layer 21i. In the step (c), the active material layer 21 is formed to include the third negative electrode active material nanoparticles. In this case, the third negative electrode active material nanoparticles may be formed of various materials, for example, may include at least one of Si, Ge, Mg, Al, P, Ga, As, Cd, Au, and Bi.

In one embodiment, the third negative electrode active material nanoparticles, like the first negative electrode active material nanoparticles of the previous step (a) and / or the second negative electrode active material nanoparticles of the previous step (b) may be Si. Therefore, the Si nanoparticles can be formed by decomposing silane gas or by pulverizing commercially available Si particles by a method such as ball milling.

As such, the active material layer 21 including the negative active material is formed on the core 10 including the negative active material and the inactive material layer 21i surrounding the active material layer 21, thereby inactivating the inactive material layer not involved in the redox reaction of the battery. The deterioration of the capacity characteristic due to (21i) can be compensated for. However, since the overall thickness of the negative electrode composition 1 may be excessively thick, the inactive material layer 21i and the active material layer 21 may be each formed to a thickness of 1 to 200 nm.

Next, (d) the step (b) and the step (c) is sequentially performed a plurality of times repeated. That is, the additional inactive material layer 22i is formed on the active material layer 21 formed in step (c), and the additional active material layer 22 is formed thereon again. In this case, the additional inert material layer 22i may be formed to include at least one of SiO ₂ , Al ₂ O ₃ , TiO ₂ , Fe ₃ O ₄ , soft carbon, hard carbon, and a polymer. The additional active material layer 22 may be formed to include at least one of Si, Ge, Mg, Al, P, Ga, As, Cd, Au, and Bi.

In one embodiment, as described above, the silane gas is decomposed to form a temporary active material layer including Si nanoparticles, and then the temporary active material layer is heat-treated in an oxygen-containing atmosphere to further inert material containing SiO ₂ . Layer 22i may be formed. Thereafter, the silane gas may be again supplied on the additional inert material layer 22i to form the additional active material layer 22 including the Si nanoparticles. Therefore, since a plurality of active material layers and an inert material layer can be formed by alternately forming a silane gas atmosphere and an atmosphere atmosphere, a negative electrode composition for a lithium secondary battery is continuously formed without expensive equipment using a laser beam or plasma. can do.

Of course, when the temporary active material layer and the additional active material layer 22 is formed, a method of grinding the commercialized Si particles by a method such as ball milling may be used.

As described above, the inactive material layer and the active material layer may be repeatedly stacked to finally form the negative electrode composition 1 for a lithium secondary battery. Accordingly, the negative electrode composition 1 for a rechargeable lithium battery according to an embodiment of the present invention includes a core 20 and a shell 20 disposed to surround at least a portion of the core 10 on the surface of the core 10. It takes the form of a core-shell structure. In this case, the shell 20 is formed such that at least one

inert material layer

21i, 22i, ... 2ni and at least one

active material layer

21, 22, ... are alternately stacked. In addition, the core 10 may be formed of the same or similar material as the at least one

active material layer

21, 22,..., So that the lowermost layer of the shell 20 in contact with the surface of the core 10 may be It is formed of an inert material layer 21i.

Meanwhile, as shown in FIG. 1, each of the at least one

inert material layer

21i, 22i, ... 2ni may be formed of the same material, and the at least one

active material layer

21, 22, ... Each may be formed of the same material. However, the present invention is not limited thereto, and some of the at least one

inert material layer

21i, 22i, ... 2ni may be formed of different materials, and at least one

active material layer

21, 22, ... Some of them may also be formed of different materials.

2 is a cross-sectional view schematically showing a negative electrode composition for a rechargeable lithium battery according to another embodiment of the present invention, and FIG. 3 is a cross-sectional view schematically showing a negative electrode composition for a rechargeable lithium battery according to another embodiment of the present invention.

2 and 3, the negative electrode composition 2 for a rechargeable lithium battery according to another embodiment of the present invention surrounds the core 10 and at least a portion of the core 10 on the surface of the core 10. The shell 20 arrange | positioned so that it may be provided, and the conductive layer 30 arrange | positioned on the shell 20 are provided. In this case, the shell 20 is formed such that at least one

inert material layer

21i, 22i, ... 2ni and at least one

active material layer

21, 22, ... are alternately stacked.

First, in the embodiment shown in FIG. 2, the conductive layer 30 is formed on the outermost side of the core-shell structure that is the same as or similar to that shown in FIG. 1. By forming the conductive layer 30 in this way, the electrical conductivity of the negative electrode composition 2 for lithium secondary batteries can be improved, and volume expansion of Si or the like contained in the core-shell structure can be further prevented.

Meanwhile, the embodiment shown in FIG. 3 is similar to the structure of the embodiment shown in FIG. 2, except that the core 10 has a hollow sphere shape. That is, the negative electrode composition 3 for a lithium secondary battery illustrated in FIG. 3 includes a core 10 having a hollow spherical shape and a shell disposed to surround at least a portion of the core 10 on the surface of the core 10. 20 and a conductive layer 30 disposed on the shell 20. In this case, the shell 20 is formed such that at least one

inert material layer

21i, 22i, ... 2ni and at least one

active material layer

21, 22, ... are alternately stacked.

Therefore, in order to form the negative electrode composition (2) (3) for the lithium secondary battery according to the embodiment shown in FIGS. 2 and 3, after the manufacturing process of the negative electrode composition (1) for the lithium secondary battery described above with reference to FIG. In addition, a process of forming the conductive layer 30 on the outermost side of the core-shell structure is additionally performed.

In one embodiment, the conductive layer 30 may include carbon as a conductive material. For example, the conductive layer 30 may include crystalline carbon such as natural graphite, artificial graphite, amorphous carbon such as soft carbon, hard carbon, or the like. Can be formed.

4 is a TEM photograph of a negative electrode composition for a rechargeable lithium battery according to an embodiment of the present invention, and FIG. 5 is an enlarged TEM photograph of part A of FIG. 4.

As shown in FIG. 4, the negative electrode composition for a rechargeable lithium battery according to an embodiment of the present invention has a spherical core and a core-shell structure formed to surround the core, which is more specifically illustrated in FIG. 5. It is. In this case, the core is formed of Si, and the shell is formed in a form in which SiO ₂ and Si are alternately stacked.

Specifically, in Fig. 5 (i) is located a spherical core containing Si, in Fig. 5 (ii) is located an inert material layer containing SiO ₂ , in Fig. 5 (iii) an active material containing Si The floor is located. In addition, in FIG. 5 (iv), the inert material layer including SiO ₂ is located, and the inactive material layer is formed to have the thinnest thickness among the shells. Wherein the core located in (i) comprises crystalline Si, the inert material layer located in (ii) comprises amorphous SiO ₂ , the active material layer located in (iii) comprises amorphous Si, and (iv) The inert material layer located at includes amorphous SiO ₂ .

As described above, the anode composition in which a shell composed of three layers around the spherical core is disposed to surround the core may have a total diameter of 80 to 100 nm.

6 is a graph showing a change in discharge capacity according to the number of cycles of a lithium secondary battery according to an embodiment and a comparative example of the present invention, Figure 7 is a cycle number of a lithium secondary battery according to an embodiment and a comparative example of the present invention This is a graph showing the change of coulombic efficiency.

6 and 7 show the result data of experiments performed under the following conditions. The lithium secondary battery sample used in the experiment was provided with a negative electrode, a positive electrode, and an electrolyte, and had a coin cell shape. At this time, the negative electrode is prepared by mixing Si nanoparticles, a conductive agent, a thickener and a binder in a ratio of 80: 10: 5: 5 and then adding water to make a slurry, and thinly applying the resulting slurry onto a copper foil.

The specific experimental method is as follows. The lithium secondary battery sample starts charging at a charge rate of 0.1 C-rate, and the voltage is charged up to 0.005V, where it is charged to have a constant voltage at a constant current. After that, the discharge is performed at a discharge rate of 0.1 C-rate, but the voltage is discharged to 1.5V, and a constant current is applied even at this time. After one charge and discharge cycle as described above, the charge and discharge cycle is repeated continuously at a voltage section of 0.005 V to 1 V at a charge and discharge rate of 0.5 C-rate.

On the other hand, in order to verify the effect of the present invention was carried out by the same method as described above with a negative electrode formed of Si nanoparticles as a comparative example.

First, referring to the graph of FIG. 6, in the case of a lithium secondary battery (indicated by a dotted line) according to an embodiment of the present invention, the discharge capacity is constant even if the number of cycles increases compared to the lithium secondary battery (indicated by a solid line) according to a comparative example. It can be confirmed that it is maintained. This means that the core (Si) -shell structured anode material as in one embodiment of the present invention shows much more stable life characteristics than a simple Si anode material.

In addition, referring to the graph of FIG. 7, the lithium secondary battery (indicated by a line connecting circular dots) according to an embodiment of the present invention is higher than the lithium secondary battery (indicated by a solid line) according to a comparative example. It can be seen that it has a coulombic efficiency (CE). This means that the core (Si) -shell structured anode material as one embodiment of the present invention has higher charge / discharge efficiency than a simple Si anode material.

That is, when applying the lithium secondary battery including the negative electrode composition according to an embodiment of the present invention, as shown in Figures 6 and 7 to prevent the occurrence of cracks due to volume expansion of the negative electrode active material and stable life characteristics and High charge and discharge efficiency can be obtained.

Referring to FIG. 8, the lithium secondary battery 100 according to an embodiment of the present invention includes a negative electrode 112, a positive electrode 114, a separator 113 disposed between the negative electrode 112 and the positive electrode 114, and a negative electrode. (112), an electrolyte (not shown) impregnated in the positive electrode 114 and the separator 113, the battery container 120, and the sealing member 140 for sealing the battery container 120 is composed as a main portion have. The lithium secondary battery 100 is manufactured by stacking the negative electrode 112, the positive electrode 114, and the separator 113 in order, and then storing the lithium secondary battery 100 in the battery container 120 while being wound in a spiral shape. At this time, the negative electrode 112 is formed of the negative electrode composition of the structure shown in Figure 1, 2 or 3, thereby minimizing the volume expansion of the high-capacity negative electrode active material to improve the life characteristics of the lithium secondary battery 100 including the same May be as described above.

Meanwhile, although the lithium secondary battery 100 is illustrated as having a cylindrical shape in FIG. 8, the lithium secondary battery 100 is not necessarily limited thereto and may be formed in various shapes such as a square shape, a coin shape, and a pouch type.

As described above, the present invention has been described with reference to one embodiment shown in the drawings, but this is merely exemplary, and it will be understood by those skilled in the art that various modifications and variations of the embodiment are possible therefrom. . Therefore, the true technical protection scope of the present invention will be defined by the technical spirit of the appended claims.

According to an embodiment of the present invention, a negative electrode composition for a lithium secondary battery may be provided to implement a high capacity negative electrode having improved lifespan, and such a negative electrode composition for a secondary battery may be a mobile mobile electronic device such as a mobile phone, a laptop, an electric vehicle, or a hybrid. It can be used in automobiles, hybrid ships, electric bicycles and the like.

Claims

core; And

A shell disposed on a surface of the core and having at least one active material layer reacting with lithium ions to produce a volume change, and at least one inert material layer having a smaller volume change rate than the at least one active material layer; The negative electrode composition for lithium secondary batteries provided.
The method of claim 1,

It is disposed on the shell, the conductive layer containing carbon; further comprising, a negative electrode composition for a lithium secondary battery.
The method of claim 1,

The core comprises Si, a negative electrode composition for a lithium secondary battery.
The method of claim 1,

The at least one active material layer comprises Si, the negative electrode composition for a lithium secondary battery.
The method of claim 1,

The at least one inert material layer includes at least one of SiO 2 , Al 2 O 3 , TiO 2 , Fe 3 O 4 , soft carbon, hard carbon, and a polymer. Negative electrode composition.
The method of claim 1,

The bottom layer of the shell, SiO 2 , Al 2 O 3 , TiO 2 , Fe 3 O 4 , soft carbon (soft carbon), hard carbon (hard carbon) and at least one of a polymer, a negative electrode composition for a lithium secondary battery.
The method of claim 1,

The core has a spherical shape,

The shell is disposed to surround at least a portion of the core, the negative electrode composition for a lithium secondary battery.
The method of claim 7, wherein

The said core has a hollow spherical shape, The negative electrode composition for lithium secondary batteries.
The method of claim 7, wherein

The at least one active material layer and the at least one inert material layer, each having a thickness of 1 to 200nm, the negative electrode composition for a lithium secondary battery.
The method of claim 7, wherein

The core has a diameter of 1 to 500nm, the negative electrode composition for a lithium secondary battery.
The method of claim 1,

The core comprises Si,

The at least one active material layer comprises Si, the at least one inert material layer comprises SiO 2 ,

The lowermost layer of the shell comprises SiO 2 , the negative electrode composition for a lithium secondary battery.
(a) forming a core including the first negative electrode active material nanoparticles;

(b) forming a temporary active material layer including second anode active material nanoparticles on the surface of the core, and then heat treating the temporary active material layer in an air atmosphere to form an inert material layer;

(c) forming an active material layer including third negative active material nanoparticles on the inactive material layer; And

(d) performing the step (b) and the step (c) by repeating a plurality of times in sequence; comprising, the negative electrode composition for a lithium secondary battery.
The method of claim 12,

(e) after the step (d), further comprising the step of forming a conductive layer containing carbon; manufacturing method of a negative electrode composition for a lithium secondary battery.
The method of claim 12,

The first negative electrode active material nanoparticles are Si, wherein Si is formed by decomposing silane gas.
The method of claim 12,

The second negative electrode active material nanoparticles are Si, wherein Si is formed by decomposing silane gas,

The inert material layer comprises SiO 2 , a method for producing a negative electrode composition for a lithium secondary battery.
The method of claim 12,

The third negative electrode active material nanoparticles are Si, wherein Si is formed by decomposing silane gas, the method for producing a negative electrode composition for a lithium secondary battery.
The method of claim 12,

The core is formed to have a spherical shape,

The active material layer and the inactive material layer is formed to surround at least a portion of the core, the manufacturing method of the negative electrode composition for a lithium secondary battery.
The method of claim 17,

The said core is formed so that it may have a hollow spherical shape, The manufacturing method of the negative electrode composition for lithium secondary batteries.
The method of claim 12,

The said active material layer and the said inactive material layer are the manufacturing methods of the negative electrode composition for lithium secondary batteries whose thickness is 1-200 nm.
The method of claim 12,

The core has a diameter of 1 to 500nm, a method for producing a negative electrode composition for a lithium secondary battery.
anode;

Electrolyte; And

The lithium secondary battery provided with; The negative electrode containing the negative electrode composition for lithium secondary batteries of any one of Claims 1-11.