KR20130002252A - Method of manufacturing composite anode material with amorphous carbon and composite anode material with amorphous carbon using thereof - Google Patents

Abstract

PURPOSE: A manufacturing method of a carbon composite negative electrode material is provided to integrate an intermetallic compound-based and transition metal oxide-based active material without influencing structural and physical properties. CONSTITUTION: A manufacturing method of a carbon composite negative electrode material comprises: a step(S1) of manufacturing a mixed solution which is mixed of solvent and a negative electrode active material with an intermetallic compound and/or transition metal oxide; a step(S2) of heating and decreasing the temperature of the mixed solution, and obtaining a mixed powder through the heat decomposition of the amorphous carbon precursor and the evaporation of the solvent; and a step(S3) heat-treating the mixed powder. The amorphous carbon composite negative electrode material comprises an intermetallic compound-based negative electrode active material and amorphous carbon, has the initial charging and discharging efficiency of 80% or more. [Reference numerals] (S1) Manufacturing a mixed solution which is mixed of a single or mixed negative electrode active material and an amorphous carbon precursor with intermetallic compounds between solvents and metals, and transition metal oxides; (S2) Obtaining mixed powder through the heat decomposition of the amorphous carbon precursor and the evaporation of the solvent by decompressing and heating the mixed solution; (S3) Heat-treating the mixed powder

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for manufacturing an amorphous carbon composite anode material for a lithium ion secondary battery, and an amorphous carbon composite anode material using the same,

The present invention relates to a method for producing an amorphous carbon composite anode material for a lithium ion secondary battery, and more particularly, to a method for manufacturing an amorphous carbon composite anode material for a lithium ion secondary battery having improved lithium ion conductivity and electronic conductivity, To an amorphous carbon composite anode material for a secondary battery.

Secondary batteries are being used as small-scale, high-performance energy sources for large-capacity power storage batteries such as electric vehicles and battery power storage systems, and portable electronic devices such as mobile phones, camcorders, and notebook computers. There is a need for a secondary battery capable of achieving a small size and a high capacity in addition to research on reduction in weight of components and reduction in power consumption aiming at miniaturization of portable electronic devices and continuous use for a long time.

Recently, the secondary battery market is rapidly expanding as a medium to large-sized power source for a hybrid electric vehicle (HEV or PHEV) as well as a portable electronic device such as a portable electronic device (a mobile phone, a notebook computer,

As a conventional negative electrode active material, various types of carbon-based materials including artificial graphite, natural graphite, and hard carbon capable of lithium insertion and desorption have been applied. Among them, the graphite material has a layered structure, which has a long life due to the reversible insertion and desorption of Li ⁺ ions, but the theoretical capacity is limited to 372 mAh / g.

Therefore, intermetallic compounds and transition metal oxide based active materials have been studied for high capacity secondary batteries. Especially, the materials of Si, Sn, SnO ₂ , and Fe ₃ O ₄ systems have a capacity two times higher than those of conventional graphite anode materials.

Among these, metals forming Li and intermetallic compounds have a volume expansion of several hundred% when they are bonded with Li. As the volume of the active material expands, cracks are formed and pulverization occurs to cause electric short circuit It is known that the charge / discharge capacity is rapidly reduced as the charge / discharge progresses.

Likewise, transition metal oxide systems also involve volume expansion of several hundreds percent, which has the problems mentioned above. In order to suppress the volume expansion, a method of reducing the particle size has been studied. However, the particles having the nanoscale size, which are prepared to suppress the volume expansion, are insulated by the quantum size confinement effect, And it is known to inhibit the stable formation of SEI film during Li ⁺ ionic conductivity, electron conductivity and initial charge / discharge.

Therefore, in order to utilize a high-capacity intermetallic compound system and a transition metal oxide system active material, development of a treatment method capable of suppressing volume expansion and improving ionic conductivity and electronic conductivity is urgently required.

SUMMARY OF THE INVENTION The present invention has been conceived to solve the above-mentioned problems, and it is a first object of the present invention to provide a method for manufacturing a semiconductor device, which is capable of forming an intermetallic compound system and a transition metal oxide- To provide a method for manufacturing an amorphous carbon composite anode material for a lithium ion secondary battery having improved lithium ion conductivity and electronic conductivity.

A second object of the present invention is to provide an amorphous carbon composite anode material for a lithium ion secondary battery having a high discharge capacity retention ratio as compared with a conventional amorphous carbon composite anode material for a lithium ion secondary battery even after several times of charge and discharge.

In order to solve the first problem of the present invention described above, (S1) a solvent; An anode active material powder in which an intermetallic compound system and a transition metal oxide system are singly or in combination; And an amorphous carbon precursor are mixed; (S2) heating the mixed solution under reduced pressure to obtain a mixed powder through pyrolysis of the amorphous carbon precursor and evaporation of the solvent; And (S3) heat-treating the mixed powder. The present invention also provides a method for manufacturing an amorphous carbon composite anode material for a lithium ion secondary battery.

According to a preferred embodiment of the present invention, the intermetallic compound-based anode active material is selected from the group consisting of silicon (Si) and tin (Si), and the transition metal oxide-based anode active material is iron oxide (Fe ₃ O ₄ ) , Tin oxide (SnO ₂ ), cobalt oxide (Co _x O), manganese oxide (Mn _x O _{y ),} and titanium oxide (TiO ₂ ).

According to another preferred embodiment of the present invention, the amorphous carbon precursor may be selected from the group consisting of malic acid, sugar (sucrose), glucose (glucose, acetic acid) and organic acids.

According to another preferred embodiment of the present invention, the organic solvent may be selected from the group consisting of toluene, hexane, benzene, benzene, xylene and ethylbenzene. have.

According to another preferred embodiment of the present invention, the step S2 may be made in a state in which the mixed solution is reduced to 0.001 to 650mmHg pressure and heated to 100 to 180.

According to another preferred embodiment of the present invention, the heat treatment in the step (S3) may be performed at a temperature of 200 to 280 ° C in a reducing atmosphere.

In order to achieve the second object of the present invention, there is provided an amorphous lithium secondary battery comprising an intermetallic compound-based anode active material and amorphous carbon and having an initial charge-discharge efficiency of 80% or more and a discharge capacity retention rate of 25% Carbon composite anode material.

According to another preferred embodiment of the present invention, the intermetallic compound anode active material may be silicon (Si).

According to another preferred embodiment of the present invention, there is provided an amorphous carbon composite anode material for a lithium ion secondary battery comprising a transition metal oxide based negative electrode active material and amorphous carbon and having a discharge capacity retention ratio of 55% or more after 50 cycles of charging / discharging .

According to another preferred embodiment of the present invention, the transition metal oxide based negative electrode active material may be iron oxide.

According to the method for producing an amorphous carbon composite anode material for a lithium ion secondary battery of the present invention, an intermetallic compound and a transition metal oxide-based active material are mixed with an amorphous carbonaceous material by thermal decomposition at a low temperature and heat treatment at a low temperature, Carbon. ≪ / RTI >

The amorphous carbon composite anode material for a lithium ion secondary battery produced according to the production method of the present invention can minimize volume expansion upon binding with lithium, and has excellent lithium ion conductivity and electron conductivity. Also, even after charging and discharging several tens of times, the discharge capacity retention rate is higher than that of the conventional amorphous carbon composite anode material for a lithium ion secondary battery.

The method for manufacturing an amorphous carbon composite anode material for a lithium ion secondary battery of the present invention can be widely used not only for manufacturing an electrode material of a secondary battery but also for improving physical properties of other nanomaterials.

1 is a process flow diagram illustrating a method for manufacturing an amorphous carbon composite anode material for a lithium ion secondary battery according to the present invention.
FIGS. 2 to 4 show structures of the iron oxide, the amorphous carbon composite (Fe ₃ O ₄ / C), the tin oxide (SnO ₂ ) and the amorphous carbon composite material and the silicon (Si) and the amorphous carbon composite material prepared in Examples 1 to 3, Ray diffraction analysis with the materials before the surface treatment.
5A is a graph showing the results of measurement of charge / discharge characteristics of a half-cell manufactured using iron oxide and an amorphous carbon composite (Fe ₃ O ₄ / C) as a negative electrode active material, respectively, at 0.02 to 3 V to C / FIG. 5B is a graph showing the results of measurement of the charge-discharge characteristics of 50 cycles of charging / discharging at 0.02 to 3 V and C / 10. FIG. (GITT), which is a polarization phenomenon, and shows the measurement results of the characteristics.
6A is a graph showing the results of measurement of charging / discharging characteristics of a half-cell made of tin oxide and an amorphous carbon composite (SnO ₂ / C) as negative electrode active material by charging / discharging at 0.05 to 1.5 V to C / And Fig. 6B is a graph showing the results of measurement of the charge-discharge characteristics of 30 cycles of charging / discharging at 0.02 to 1.5 V at C / 10.
7A is a graph showing the results of measurement of the characteristics of a half-cell manufactured using a silicon (Si) and an amorphous carbon composite material (Si / C) as an anode active material at an initial charge / discharge of 0.01 to 1.5 V to C / And FIG. 7B is a graph showing the results of measurement of the charge-discharge characteristics of the second cycle at a rate of 0.01 to 1.5 V by performing charge and discharge at 50 cycles at C / 5.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein.

As described above, the negative electrode material composed of an intermetallic compound system and / or a transition metal oxide system and carbon has not only a remarkably high volume expansion rate but also a low ion conductivity and an electron conductivity. As a result, there has been a problem that the discharge capacity retention rate drops suddenly after several tens of charge / discharge cycles.

Accordingly, in the present invention, (S1) a solvent; An anode active material powder in which an intermetallic compound system and a transition metal oxide system are singly or in combination; And an amorphous carbon precursor are mixed; (S2) heating the mixed solution under reduced pressure to obtain a mixed powder through pyrolysis of the amorphous carbon precursor and evaporation of the solvent; And (S3) heat-treating the mixed powder. The present invention has been made to solve the above-mentioned problems by providing a method for manufacturing an amorphous carbon composite anode material for a lithium ion secondary battery. The amorphous carbon composite anode material for a lithium ion secondary battery produced through the above process is characterized in that an intermetallic compound and a transition metal oxide based active material are complexed with amorphous carbon under specific conditions so that lithium ion conductivity and electronic conductivity Improvement is improved.

1 is a process flow diagram illustrating a method for manufacturing an amorphous carbon composite anode material for a lithium ion secondary battery according to the present invention. A method of manufacturing an amorphous carbon composite anode material for a lithium ion secondary battery according to the present invention will be described with reference to FIG.

First, a solvent; An anode active material powder in which an intermetallic compound system and a transition metal oxide system are singly or in combination; And an amorphous carbon precursor are mixed (S1).

The intermetallic compound-based anode active material is selected from the group consisting of silicon (Si) and tin (Sn), and the transition metal oxide-based negative electrode active material may be selected from the group consisting of iron oxide (Fe _x O _y ), tin oxide SnO ₂ ), cobalt oxide (Co _x O), manganese oxide (Mn _x O _{y )} , and titanium oxide (TiO ₂ ).

The amorphous carbon precursor is preferably selected from the group consisting of, for example, malic acid, sucrose, glucose, acetic acid and organic acids.

The solvent is preferably an organic solvent selected from the group consisting of, for example, toluene, hexane, benzene, xylene, ethylbenzene and an organic solvent.

In step (S1), 0.5 to 10 parts by weight of an intermetallic compound-based or transition metal oxide-based negative electrode active material powder based on 100 parts by weight of the organic solvent is preferably added.

When the intermetallic compound-based or transition metal oxide-based negative electrode active material powder is added in an amount of more than 10 parts by weight based on 100 parts by weight of the organic solvent, there arises a difference in the uniformity of the surface of the amorphous carbon and the degree of amorphous carbon composites of each particle. The amount of amorphous carbon is increased due to a change in the fraction of the amorphous carbon and the negative electrode active material, so that the energy density of the electrode is decreased, which is not preferable.

It is also preferable to add 0.5 to 10 parts by weight of the amorphous carbon precursor based on 100 parts by weight of the organic solvent.

When the amorphous carbon precursor is added in an amount of more than 10 parts by weight based on 100 parts by weight of the organic solvent, the amount of amorphous carbon is increased due to a change in the fraction of the amorphous carbon and the negative active material, The amount of amorphous carbon and the composition of amorphous carbon in the amorphous carbon are different from each other due to the variation of the fraction of the amorphous carbon and the anode active material and thus the effect on the improvement of the electronic conductivity and ion conductivity is insufficient have.

Next, the mixed solution is heated under reduced pressure to pyrolyze the amorphous carbon precursor and evaporate the solvent to obtain a mixed powder (S2). This step will be described in more detail. When the mixed solution is heated by heating in an oil bath using an oil bath, the chain structure of the amorphous carbon precursor such as malic acid is broken and decomposed to cover the precursor. In this step, the solution is evacuated by using a pump together with heating, and the pressure inside the flask is continuously reduced to evaporate the solution.

The step S2 is preferably carried out in a state in which the mixed solution is reduced to 0.001 to 650mmHg pressure and heated to 100 to 180.

Next, the mixed powder is heat-treated (S3).

In the step (S3), the heat treatment is preferably performed at a temperature of 200 to 280 DEG C in a reducing atmosphere. If the heat treatment temperature exceeds the upper limit of the above range, the physical structure of the intermetallic compound system and the transition metal oxide precursor may change due to the energy due to the high temperature. If the heat treatment temperature is below the lower limit of the above range, The bonding of -OH, -OOH, -H, etc. bonded to the carbon of the precursor is not completely decomposed, which is not preferable.

The reducing atmosphere at the time of the heat treatment may be a nitrogen atmosphere, argon (Ar), helium (He), neon (Ne), xenon (Xe) gas atmosphere or vacuum atmosphere.

By using the above-described method for producing an amorphous carbon composite anode material for a lithium ion secondary battery of the present invention, it is possible to produce an intermetallic compound system and a transition metal oxide system active material by thermal decomposition at a low temperature and heat treatment at a low temperature without affecting the structural and physical properties Can be complexed with amorphous carbon.

The amorphous carbon composite anode material for a lithium ion secondary battery produced according to the production method of the present invention can minimize volume expansion upon binding with lithium, and has excellent lithium ion conductivity and electron conductivity.

More specifically, the amorphous carbon composite anode material for a lithium ion secondary battery produced by the method of the present invention includes an intermetallic compound-based anode active material and amorphous carbon, and has an initial charge-discharge efficiency of 80% or more, The capacity retention rate can be maintained at 25% or more. In this case, the intermetallic compound-based negative electrode active material may be silicon (Si) (see FIGS. 5A and 5B).

According to another preferred embodiment of the present invention, the amorphous carbon composite anode material for a lithium ion secondary battery includes a transition metal oxide-based anode active material and amorphous carbon, and the discharge capacity retention rate can be maintained at 55% or more after 50 charge / discharge cycles 7a and 7b).

INDUSTRIAL APPLICABILITY The method for producing an amorphous carbon composite anode material for a lithium ion secondary battery according to the present invention is characterized in that the powder to be compounded with amorphous carbon is selected from a variety of intermetallic compounds or transition metal oxide powders, It can be widely used for improvement of physical properties.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the present invention. Such variations and modifications are intended to be within the scope of the appended claims.

Example  One

0.1 g of malic acid was dissolved in 20 ml of toluene, 0.1 g of iron oxide powder was added, and the mixture was stirred for 2 hours to prepare a mixed solution. Thereafter, the prepared mixed solution was maintained at 180 캜 for 6 hours under a reduced pressure of 650 mmHg atmospheric pressure to obtain a composite powder. Next, the composite powder was heat-treated at 265 캜 for 3 hours in an Ar atmosphere to produce an amorphous carbon composite anode material.

Example  2

0.1 g of malic acid was dissolved in 20 ml of toluene, 0.1 g of tin oxide powder was added, and the mixture was stirred for 2 hours to prepare a mixed solution. Thereafter, the prepared mixed solution was maintained at 180 캜 for 6 hours under a reduced pressure of 650 mmHg atmospheric pressure to obtain a composite powder. Next, the composite powder was heat-treated at 265 캜 for 3 hours in an Ar atmosphere to produce an amorphous carbon composite anode material.

Example  3

0.1 g of malic acid was dissolved in Ar / H ₂ atmosphere, and 0.1 g of silicon powder was added to 20 ml of toluene, followed by stirring in an Ar / H ₂ atmosphere for 2 hours to prepare a mixed solution. Thereafter, the prepared mixed solution was maintained at 180 캜 for 6 hours under a reduced pressure of 650 mmHg atmospheric pressure to obtain a composite powder. Next, the composite powder was heat-treated at 265 ° C in an Ar / H ₂ atmosphere for 3 hours to produce an amorphous carbon composite anode material.

Test Example  1 - X-ray diffraction  analysis

In order to analyze the structures of the iron oxide, the amorphous carbon composite (Fe ₃ O ₄ / C), the tin oxide (SnO ₂ ) and the amorphous carbon composite material and the silicon (Si) and the amorphous carbon composite material prepared in Examples 1 to 3, X-ray diffraction analysis was carried out with the materials before the surface treatment, respectively, and the results are shown in FIG. 2, FIG. 3 and FIG.

Iron oxide (Fe ₃ O ₄ ) shown in FIG. 1 was pyrolyzed under reduced pressure as a control group in order to confirm the effectiveness of the heat treatment and reducing atmosphere, and a composite powder of iron oxide (Fe ₃ O ₄ ) and amorphous carbon And those performed in air at the time of heat treatment are shown together.

As can be seen in FIG. 2, there is no significant change in the crystal structure of iron oxide (Fe ₃ O ₄ ) according to each variable, and all of them have a cubic structure. FWHM (Fe ₃ O ₄ ) crystal structure and particle size from the particle size obtained from the Full Width Half Maximum calculation.

The X-ray diffraction analysis of FIG. 3 shows that the crystal structure of the tin oxide, the amorphous carbon composite (SnO ₂ / C) and the tin oxide (SnO ₂ ) does not change much, and both have a tetragonal rutile structure. In addition, broad peaks of low angle seen in tin oxide (SnO ₂ ) and amorphous carbon composite show that amorphous carbon is formed.

The X-ray diffraction analysis of FIG. 4 confirmed that the crystal structure was not influenced by both the silicon (Si) and amorphous carbon composite (Si / C) exhibiting diamond cubic crystal structure. However, the peak of amorphous carbon at low angle is difficult to confirm due to the high crystallinity of silicon (Si).

Test Example  2 - Charging and discharging  Characteristics and coulomb  Efficiency analysis

A half-cell made of iron oxide and an amorphous carbon composite (Fe ₃ O ₄ / C) as a negative electrode active material was charged and discharged at 0.02 to 3 V to C / 10, and the measurement results of the charge- Respectively. Further, charging and discharging were performed for 50 cycles at 0.02 to 3 V and at C / 10, and the results of the measurement of the charge-discharge characteristics are shown in FIG. 5B.

Then, a galvanostatic intermittent titration technique (GITT) showing polarization due to overvoltage was performed during charging from 0.02 to 3 V to 0.1 C, and the measurement result of the characteristics is shown in FIG. 5C.

As shown in FIG. 5A, the iron oxide and the amorphous carbon composite (Fe ₃ O ₄ / C) exhibit oxidation / reduction reactions such as iron oxide (Fe ₃ O ₄ ), and iron oxide Amorphous carbon composites (Fe ₃ O ₄ / C) show higher capacity than iron oxide (Fe ₃ O ₄ ). As a control, evaluation results of iron oxide and amorphous carbon composite (Fe ₃ O ₄ / C) produced by heat treatment in an atmospheric environment and those without heat treatment were also shown.

Referring to FIG. 5B, in the lithium ion battery, the discharge capacity retention rate after 60 cycles of charging / discharging is 60%, which shows a very high rate of increase compared with the 9% retention rate of iron oxide (Fe ₃ O ₄ ) Seems to be maintained. FIG. 5C is a graph showing the measurement results of the galvanostatic intermittent titration technique (GITT) showing polarization due to overvoltage during charging from 0.02 to 3V to 0.1C.

From the above results, the iron oxide and amorphous carbon composite (Fe ₃ O ₄ / C) of the present invention have an electrochemical reaction mechanism such as a control iron oxide (Fe ₃ O ₄ ) It was found that the carbon composite was improved as compared with iron oxide (Fe ₃ O ₄ ) to improve the electronic conductivity and ionic conductivity, and thus reversible reaction occurred during charging and discharging, and it was suitable as a cathode material for a lithium secondary battery having a long life .

*

A half cell made of tin oxide and an amorphous carbon composite material (SnO ₂ / C) as a negative electrode active material was charged and discharged at 0.05 to 1.5 V to C / 10, respectively. The results of the charge / . Further, charging and discharging were performed for 30 cycles at 0.02 to 1.5 V and at C / 10, and the results of the measurement of the charge-discharge characteristics are shown in FIG. 6B.

6A shows that the initial irreversible capacity of tin oxide and amorphous carbon composite (SnO ₂ / C) is 732 mAh / g, which is much smaller than the irreversible capacity of 1277 mAh / g of tin oxide (SnO ₂ ). Correspondingly, initial charge efficiency improved from 31.01% to 44.87%. In addition, the lithium oxide (Li ₂ O) is approximately plane (plateau) 0.9V potential of the flat for the formation shrink as Li ⁺ insertion and desorption of lithium oxide during ion electric ago by the (Li ₂ O) indicate that the short is reduced have.

FIG. 6B shows that the tin oxide and amorphous carbon composite (SnO ₂ / C) maintains a capacity of about 400 mAh / g after 30 cycles and exhibits a reversible electrochemical reaction compared to tin oxide (SnO ₂ ). In addition, the rate of reduction of tin oxide (SnO ₂ ) was 2.46% compared to that of the second cycle, while that of tin oxide and amorphous carbon (SnO ₂ / C) was 1.28%.

From the above results, it can be seen that the tin oxide and amorphous carbon composite (SnO ₂ / C) of the present invention inhibit the formation of a lithium oxide (Li ₂ O) phase which causes electrical shorting compared to the control tin oxide (SnO ₂ ) The electron conductivity and the ionic conductivity due to the complexation were improved, so that a reversible reaction occurred during charging and discharging, and it was found to be suitable as a negative electrode material for a lithium rechargeable battery having a long lifetime.

A half-cell made of silicon (Si) and an amorphous carbon composite material (Si / C) as negative electrode active materials was subjected to initial charging and discharging at 0.01 to 1.5 V to C / 20, respectively. . The second cycle at 0.01 to 1.5 V was charged / discharged 50 times at C / 5, and the results of the measurement of the charge-discharge characteristics are shown in Fig. 7B.

In FIG. 7a, the initial efficiency of the amorphous carbon composite material (Si / C) was 88.66%, which was significantly improved compared to 72.51% of silicon (Si), and irreversible capacities were 391mAh / g and 1031mAh / g, respectively. It is considered that the improvement of the initial efficiency is due to the increase of the electric conductivity and the ion conductivity of the silicon surface due to the complexation of amorphous carbon.

In FIG. 7B, after 15 charge / discharge cycles in a lithium ion battery manufactured using silicon (Si) and an amorphous carbon composite material (Si / C), the discharge capacity retention rate after 30 cycles of 15% 10% retention rate.

As a result, the initial charge / discharge efficiency of silicon (Si) and amorphous carbon composite material (Si / C) of the present invention increased from 72.51% to 88.66% as compared with the control silicon (Si) It can be seen that the conductivity and the ion conductivity are improved.

The present invention can be widely used in the field of lithium secondary batteries.

Claims (10)

(S1) a solvent; An anode active material powder in which an intermetallic compound system and a transition metal oxide system are singly or in combination; And an amorphous carbon precursor are mixed;
(S2) heating the mixed solution under reduced pressure to obtain a mixed powder through pyrolysis of the amorphous carbon precursor and evaporation of the solvent; And
(S3) A method of manufacturing an amorphous carbon composite negative electrode material for a lithium ion secondary battery, comprising the step of heat treating the mixed powder. The method of claim 1,
The intermetallic compound anode active material is selected from the group consisting of silicon (Si) and tin (Si)
The transition metal oxide-based negative electrode active material is composed of iron oxide (Fe ₃ O ₄ ), tin oxide (SnO ₂ ), cobalt oxide (Co _x O), manganese oxide (Mn _x O _{y )} and titanium oxide (TiO ₂ ) Wherein the positive electrode active material is selected from the group consisting of lithium carbonate, lithium carbonate, and lithium carbonate. The method of claim 1,
The amorphous carbon precursor is malic acid (malic acid), sugar (sucrose), glucose (glucose, acetic acid) and a method for producing an amorphous carbon composite anode material for a lithium ion secondary battery, characterized in that selected from the group consisting of organic acids. The method of claim 1,
The organic solvent is to prepare an amorphous carbon composite anode material for a lithium ion secondary battery, characterized in that selected from the group consisting of toluene (hexane), hexane (Hexane), benzene (xylene), xylene and ethylbenzene (ethylbenzene) Way. The method of claim 1,
The step S2 is a method for producing an amorphous carbon composite negative electrode material for a lithium ion secondary battery, characterized in that the mixed solution is reduced to 0.001 to 650mmHg pressure and heated to 100 to 180. The method of claim 1,
Heat treatment in the step (S3) is a method of manufacturing an amorphous carbon composite negative electrode material for a lithium ion secondary battery, characterized in that carried out at a temperature of 200 to 280 in a reducing atmosphere. An amorphous carbon composite anode material for lithium ion secondary batteries including an intermetallic compound-based negative active material and amorphous carbon, having an initial charge / discharge efficiency of 80% or more, and a discharge capacity retention rate of 25% or more after 15 charge / discharge cycles. The amorphous carbon composite negative electrode material of claim 7, wherein the intermetallic compound-based negative active material is silicon (Si). An amorphous carbon composite negative electrode material for a lithium ion secondary battery including a transition metal oxide-based negative active material and amorphous carbon, and having a discharge capacity retention rate of 55% or more after 50 charge / discharge cycles. 10. The amorphous carbon composite anode material of claim 9, wherein the transition metal oxide-based anode active material is iron oxide.

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