WO2006071076A1

WO2006071076A1 - Non-carbon material-inserted spherical carbonaceous powder and process for preparation thereof

Info

Publication number: WO2006071076A1
Application number: PCT/KR2005/004606
Authority: WO
Inventors: Cheol Wan Park; Im Goo Choi; Kyeong Jik Lee; Hyung Dong Lee; Sang Eun Lee; In Ho Ha; O Chang Kwon; Young Ju Han
Original assignee: Sodiff Advanced Materials Co., Ltd.
Priority date: 2004-12-30
Filing date: 2005-12-28
Publication date: 2006-07-06
Also published as: KR20060077359A; CN101094806A; JP2008526664A; KR100639889B1

Abstract

The present invention relates to a non-carbon material-inserted spherical carbonaceous powder comprising spherules formed from randomly agglomerated carbon thin flakes having an average size of 0.1 to 40 μm, the spherules having pores formed between the layers of the thin flakes, and a non-carbon material inserted into the pores. The inventive spherical carbonaceous powder has a high density, high strength, and enhanced lithium storage capacitance, thus exhibiting high energy density and high capacitance, and therefore, it can be beneficially used in a lithium secondary battery.

Description

NON-CARBON MATERIAL-INSERTED SPHERICAL CARBONACEOUS POWDER AND PROCESS FOR PREPARATION

THEREOF

Field of the Invention

The present invention relates to a non-carbon material-inserted spherical carbonaceous powder useful as a negative electrode active material of a non-aqueous lithium secondary battery, and the process for the preparation thereof.

Background of the Invention

With the recent rapid popularization of mobile telephones, laptop computers, and digital hand cameras, it has become necessary to improve the power density and the energy density of a secondary battery used in such instruments as a power source. Thus, many attempts have been made to develop new positive and negative electrode active materials of lithium secondary batteries having improved performance characteristics. A graphite-based material has been used as a negative electrode active material of a lithium secondary battery owing to its good performance characteristics in terms of, e.g., reliability, the battery discharge characteristics, cycle life and safety. In a lithium secondary battery comprising a graphite- based material, lithium ions cannot pass through the basal graphene plane (a hexagonal net structured face) of the crystalline graphite because of the size limitation of the hexagonal cavity of the graphene, and thus they pass through the edge of a plane perpendicular to the basal plane to be intercalated between graphite layers, in the charging process of the battery.

A highly crystalline natural graphite having a capacity density close to the theoretical capacity density of graphite (i.e., 372 mAh/g) has the drawback that it is difficult to achieve a high charge discharge efficiency and a long life. To solve such problems, Brooks, J. D. et al. suggested a synthetic graphite

- i - material in Carbon 3, 185, 1965, but it does not provide good battery characteristics due to the fact that when lithium ions are electrochemically intercalated, the space between graphite crystal layers expands by maximum 10%, thus weakening the interlay er bonding force of the crystal, leading to the delamination of the layers after repeated charge-discharge cycles.

In order to solve such problem of the graphite crystal structure disintegration caused by interlayer delamination, USP 6,403,259 suggests a method of coating the edge face of the graphite material with a low temperature-sintered carbonaceous material. But it has various problems including a reduction of the intercalated amount of lithium ions due to the coated material, an increase of initial charging irreversibility, and lowering of negative electrode characteristics. Further, Japanese Patent Application No. 2000-261046 discloses a method of coating the surface of a synthetic graphite material in the form of a spherical or fibric body such as mesocarbon microbeads (MCMB) or mesocarbon fiber (MCF) with a hard non-melting film. However, this method has the disadvantages that the synthetic graphite material is too expensive and has a lower energy density than that of a natural graphite crystal.

Accordingly, there has been a recent attempt to develop a method of manufacturing a composite of a highly crystalline natural graphite with a low temperature-sintered carbon or a polymer in order to compensate for the drawback of the natural graphite (see U.S.P. No. 6,589,696). But the resulting composite also has disadvantages in that they are not suitable for large current discharge because the mobility of lithium ions in the layer thereof is much slower than in a graphite crystal layer, and that the electric potential required for removing lithium intercalated in said composite is higher than in case for a graphite crystal, which makes the discharge curve unstable and lowers the operating voltage of the battery comprising such composite. Summary of the Invention

Accordingly, it is an object of the present invention to provide a novel spherical carbonaceous powder having good physical properties such as a high density and high strength, and good energy density achieved by a high lithium storage capacitance, and the process for the preparation thereof.

In accordance with one aspect of the present invention, there is provided a non-carbon material-inserted spherical carbonaceous powder comprising spherules formed from randomly agglomerated carbon thin flakes having an average size of 0.1 to 40 βh, the spherules having pores formed between the layers of the thin flakes, and a non-carbon material inserted into the pores.

In accordance with another aspect of the present invention, there is provided a process for preparing a non-carbon material-inserted spherical carbonaceous powder comprising the steps of mixing carbon thin flakes with a gaseous or powdered non-carbon material under a nitrogen or inert gas atmosphere and pressurizing the resulting mixture while rotating.

Brief Description of the Drawings

The above and other objects and features of the present invention will become apparent from the following description thereof, when taken in conjunction with the accompanying drawings which respectively show:

FIG. 1 : a schematic diagram showing the process of preparing a spherule of a carbon material by rotative pressurization;

FIGS. 2A through 2D : schematic diagrams showing the process of preparing the non-carbon material-inserted spherical carbonaceous powder according to various embodiments of the present invention; and

FIG 3 : a schematic diagram showing the process of coating the non- carbon material-inserted spherical carbonaceous powder. Detailed Description of the Invention

The inventive non-carbon material-inserted spherical carbonaceous powder is characterized in that thin flakes of carbon material having an average size of 0.1 to 40 μm are distributed randomly in all directions to form a basic framework of a spherical powder (spherule), and non-carbon material is inserted into pores present between the layers of thin flakes.

Herein, the term "carbonaceous powder" is collectively referred to a powder of a carbon material such as graphite, a hard carbon and a soft carbon. The inventive non-carbon material-inserted spherical carbonaceous powder may be prepared by mixing carbon thin flakes with a gaseous or powdered non-carbon material under a nitrogen or inert gas atmosphere and rotatively pressurizing the resulting mixture.

In the present invention, when the non-carbon material employed is of a gaseous form, the mixture of carbon thin flakes with the gaseous non-carbon material may be heat-treated before or after the rotative pressurizing step thereof.

Further, in accordance with the present invention, the carbon thin flakes may be subjected to a rotative pressurizing step before mixing with the non-carbon material, to form spherules, which may be then pressurized under a nitrogen or inert gas atmosphere, mixed with a gaseous non-carbon material and heat-treated.

During the procedure for converting the carbon thin flakes into spherules by a rotatively pressurizing method according to the present invention, the carbon thin flakes are forced to randomly agglomerate to form spherules with pores having an average size of 10 nm to 10 ^m₅ into which non-carbon materials are inserted, as shown in FIG. 1.

The non-carbon material to be inserted in the pores may be a single metallic component, an alloy of two or more metallic components, or a metal oxide or nitride.

In the present invention, the single metallic component may be selected from the group consisting of the elements of Groups III, IV, and V of the Periodic Table. Representative examples of the single metallic component include silicon (Si), germanium (Ge), lead (Pb), aluminium (Al), antimony (Sb) and bismuth (Bi).

Further, when an alloy is employed, it may be preferably comprised of one element selected from the single metallic components mentioned above and at least one elements selected from Groups I and II metals and transition metals of the Periodic Table. Representative examples of the alloy include a suicide such as Mg₂Si, CrSi₂ and NiSi, a tin compound such as Cu₆Sn₅, Sn₂Fe, SnSb, Sn₂Mn and Sn₂Co, an aluminide such as Al₂Cu, and an antimonide such as CuSb and InSb.

The metal oxide may be a compound represented by M_xO_y (where M is the single metallic component as mentioned previously or a transition metal, and x and y are each independently a number in the range of 1 to 5), and representative examples thereof may include a silicon oxide such as SiO and SiO₂, a tin oxide such as SnO and SnO₂, a cobalt oxide such as CoO and

Co₃O₄, an iron oxide such as Fe₂O₃, and a nickel oxide such as NiO and NiO₂.

The metal nitride may be one of the compounds represented by M_xN_y,

Li_3-XM_XN, and Li_2x-1MN_x (where M is the single metallic component as mentioned previously or a transition metal, and x and y are each independently a number in the range of 1 to 5), and representative examples thereof may include Sn₃N₄, Ge₃N₄, Li_{2 6}Co₀^N, Li_{2 6}Ni₀.₄N, Li_2-6Cu_0-4N, Li₇MnN₄, Li₇BN₄, Li₇FeN₄, and Li₇AlN₄.

Preferred embodiments of the inventive process may include the followings: (A) a process of mixing carbon thin flakes with a powdered non- carbon material under a nitrogen or inert gas atmosphere, and rotatively pressurizing the resulting mixture, as shown in FIG. 2A,

(B) a process of pressurizing carbon thin flakes under a nitrogen or inert gas atmosphere and mixing with a gaseous non-carbon material such as a metal hydride, and heat-treating and pressurizing the resulting mixture while rotating, as shown in FIG. 2B,

(C) a process of rotatively pressurizing carbon thin flakes to form spherules, mixing the spherules with a gaseous non-carbon material such as a metal hydride while pressurizing under a nitrogen or inert gas atmosphere, and heat-treating the resultant, as shown in FIG. 2C, and

(D) a process of rotatively pressurizing a mixture of carbon material flakes with a gaseous non-carbon material such as a metal hydride and heat- treating the resultant, as shown in FIG. 2D.

In the above processes, the carbon material preferably has an average particle size of 1 P to 10 mm, preferably 5 IM to 1,000 m, and more preferably 10 m to 500 m. Further, the powdered non-carbon material used in Process (A) may have an average particle size of 1 nm to 1 mm, and preferably 10 nm to 10 μm, and may be made of a single metallic component or an alloy thereof, or a metal oxide or nitride having a capacitance density higher than the theoretical capacity density of graphite, i.e., 372 mAh/g. The non-carbon material may be inserted in an amount of 1 to 70% by volume, preferably 20 to 40 % by volume based on the carbonaceous material.

The gaseous non-carbon material used in Processes (B) to (D) may be preferably a metal hydride represented by M_xH_y (where M is the single metallic component as mentioned previously, and x and y are each a number in the range of 1 to 5), and representative examples thereof include silicon hydride (SiH₄), germanium hydride (GeH₄), tin hydride (SnH₄), lead hydride (Pb₂H₂), antimony hydride (SbHs), and bismuth hydride (BiHβ). The gaseous non-carbon material may be employed at a flow rate of 0.03 to 0.1 U /minute per 1 g of the carbonaceous material. The inert gas may be argon or helium, and the rotatively pressurizing process may be carried out under the condition that generates a shear stress of 1 to 1,000 kg/cnf and a tangential velocity of 300 to 20,000 mm/sec.

In the present invention, the rotatively pressurizing process may be performed by using a conventional spherule forming apparatus equipped with a rotor having pins into which a powder is transferred by the action of a suction wind generated by a motor. The carbonaceous powder transferred to the spherule-forming apparatus is converted to spherules by the rotatively pressurizing motion of the rotor.

The spherical carbonaceous powder obtained by the inventive process has a high density and strength due to the incorporation of a non-carbon material into the pores of the spherules, and it has a good lithium storage capacitance due to a high energy density of the non-carbon material.

In accordance with the present invention, the non-carbon material- inserted spherical carbonaceous powder may be further coated, for the purpose of removing any metallic impurity present on the surface of the spherule which may influence the volume, the electric conductivity, and the affinity with oxygen of the sphereule, as schematically shown in FIG. 3. The coating process may be conducted by mixing the spherical carbonaceous powder with a coating material, rotatively pressurizing the resulting mixture, and heating and carbonizing the resultant at a temperature of 100 to 3,000 ^°C , preferably 1,200 to 3,000 "C to remove impurities present on the surface of the powder, thus improving the surface properties of the powder. The coating material may include a petroleum pitch, coal tar pitch or thermoplastic resin.

The inventive non-carbon material-inserted spherical carbonaceous powder has an improved density and strength due to the presence of non- carbon material in the pores bormed between thin carbon flaks. It also has an improved lithium storage, a higher capacitance per a unit volume or weight, and a stable life-time characteristic owing to the absence of its volme change and its enhanced electric conductivity. Accordingly, the inventive powder may be beneficially used to miniaturize a high energy density lithium secondary battery and a portable device.

The present invention is illustrated in detail by the following Examples which are not intended to limit the scope of the invention.

Example 1 : Preparation of non-carbon material-inserted spherical carbonaceous powder according to Process (A)

1.4 kg of natural graphite thin flakes was pulverized to an average size of 50 IM and the resulting powder was charged into a spherule forming apparatus under argon gas atmosphere together with 0.56 kg of a silicon powder having an average particle diameter of 2 IM. The resulting mixture was blended at an initial rotating speed of 300 mm/sec at room temperature for 1 minutes. The stirred mixture was rotatively pressurized at a shear stress of 350 kg/cnf and a tangential velocity of 1,100 mm/second for 1 hour, to produce a spherical carbonaceous powder having an average particle diameter of 18 IM (see FIG. 2A), the pores thereof containing inserted silicon particles.

Example 2: Preparation of non-carbon material-inserted spherical carbonaceous powder according to Process (B)

1.4 kg of hard carbon thin flakes was pulverized to an average size of 50 IM and the resulting powder was charged into a spherule forming apparatus under argon gas atmosphere. The pressure of the apparatus was reduced to about 500 mmHg, and then, silicon hydride (SiH₄) gas was introduced thereto at a flow rate of 100 £/min for 5 minutes. The temperature of the apparatus was increased to 200 ^°C to incur the decomposition of the silicon hydride gas. Hydrogen gas generated by the decomposition was allowed to be vented via an outlet and the apparatus was maintained to be an atmospheric pressure. The resultant was rotatively pressurized at a shear stress of 350 kg/cnf and a tangential velocity of 1,100 rom/second for 1 hour, to produce a spherical carbonaceous powder having an average particle diameter of 18 IM (see FIG. 2B), the pores thereof containing inserted silicon particles.

Example 3: Preparation of non-carbon material-inserted spherical carbonaceous powder according to Process (C)

1.4 kg of synthetic graphite thin flakes was pulverized to an average size of 50 IM and the resulting powder was charged into a spherule forming apparatus and rotatively pressurized at a shear stress of 350 kg/ cm² and a tangential velocity of 1,100 mm/second to produce a spherical carbonaceous powder. Argon gas was charged to the apparatus to maintain the apparatus at an inert atmosphere, and then the pressure of the apparatus was reduced to about 500 mmHg. Silicon hydride gas was introduced to the apparatus at a flow rate of 100 t/min for 5 minutes, and the temperature of the apparatus was increased to 200 ^°C to incur the decomposition of the silicon hydride gas. Hydrogen gas generated by the decomposition was allowed to be vented via an outlet while the apparatus was maintained to be an atmospheric pressure, to obtain a spherical carbonaceous powder having an average particle diameter of 18 μm (see FIG. 2C), the pores thereof containing inserted silicon particles.

Example 4: Preparation of non-carbon material-inserted spherical carbonaceous powder according to Process (D)

1.4 kg of a cokes powder was pulverized to an average size of 50 βn and the resulting powder was charged into a spherule forming apparatus maintained to be an inert atmosphere of argon and a silicon hydride gas was introduced thereto at a flow rate of 100 £/min for 5 minutes. The resulting mixture was rotatively pressurized at a shear stress of 350 kg/cnf and a tangential velocity of 1,100 mm/second to produce a spherical carbonaceous powder. Thereafter, the pressure of the apparatus was reduced to about 500 mmHg, and the temperature of the apparatus was increased to 200 °C to incur the decomposition of the silicon hydride gas. Hydrogen gas generated by the decomposition was vented via an outlet while the apparatus was maintained to be an atmospheric pressure, to obtain a spherical carbonaceous powder having an average particle diameter of 18 β® (see FIG. 2D), the pores thereof containing inserted silicon particles.

Examples 5 to 8: Coating of non-carbon material-inserted spherical carbonaceous powder

10 kg of each spherical carbonaceous powder obtained in Examples 1 to 4 having an average particle diameter of 18 IM was homogeneously mixed with 2 kg of a petroleum mesophase pitch in a double-cylidrical rotatively- pressurizing mill maintained at an argon gas atmosphere, and the resulting mixture was rotatively pressurized at a tangential velocity of 11,500 mm/second to produce a surface-coated spherical carbonaceous powder. The powder thus coated was heated to 1,200 ^°C for 10 hours under the argon gas atmosphere to carbonize the mesophase pitch, to obtain a coated, non-carbon material-inserted spherical carbonaceous powder having an average particle diameter of 20 m.

Comparative Example 1 : Preparation of coated spherical carbonaceous powder

1.4 kg of natural graphite thin flakes was pulverized to an average size of 50 IM was charged into a spherule forming apparatus and the resulting powder was rotatively pressurized at a shear stress of 350 kg/ cm² and a tangential velocity of 1,100 mm/second for 1 hour to produce a spherical carbonaceous powder (see FIG. 1), which was coated in the same process as described in Examples 5 to 8, to obtain a coated spherical carbonaceous powder having an average particle diameter of 20 β®.

Comparative Example 2: Preparation of carbon-noncarbon composite

7Og of natural graphite thin flakes was pulverized to an average size of 50 IM and the resulting powder was mixed with 30g of silicon powder having an average diameter of 2 IM under an argon atmosphere. The resulting mixture was ball-milled at a rotation speed of 200 rpm for 5 hours using balls in an amount so that the weight ratio of raw materials to balls to be 1 :8, to produce a carbon-silicon composite having an average particle diameter of 3 μm.

- io - Test example

The coated non-carbon material-inserted spherule carbonaceous powders obtained in Examples 5 to 8, the coated spherule carbonaceous powder obtained in Comparative Example 1, and the carbon-noncarbon composite obtained in Comparative Example 2 were each tested to evaluate the performance as a negative electrode active material of a lithium secondary battery, as follows.

Each powder was mixed with Super P Black (a product of MMM Carbon Corporation) as a conductive material and polyvinylidene fluoride (a product of Aldrich Co.) as a binder in a mix ratio of 70:20:10 by weight. The resultant mixture was cast on a copper foil current collector, dried and compressed to prepare a negative electrode plate, which was successively laminated with a separator film and a lithium electrode to fabricate a half cell for a lithium secondary battery. The lithium metal used as a reference electrode and the separator film were commercially purchased, and used in the experiment without further purification, while the electrolyte was a 1 : 1 (by volume) mixed solution of ethylene carbonate (EC) containing IM lithium hexaflouride (LiPF₆) and diethyl carbonate (DEC) (Starlyte™ of Cheil Industries Inc. of Korea).

The half cell was subjected to a charge-discharge test to determine the charge and discharge capacities thereof using an electric current density of 37 mA/a unit weight. At this time, the charge/discharge cut-off was adjusted to electric potentials of 0 V and 3 V, respectively, and the procedure was repeated 10 times to obtain average values.

Table 1

As shown in Table 1, the coated spherule carbonaceous powder obtained in Comparative Example 1 exhibit a low capacity of approximately 350 mAh/g for 10 times, and in case of the carbon-noncarbon composite obtained in Comparative Example 2, the characteristic of charge/discharge capacity is drastically reduced as the charge/discharge cycle is repeated. On the other hand, each of the half cells comprising the coated non-carbon material-inserted spherule carbonaceous powder obtained in Examples 5 to 8 held a high charge/discharge capacity when the charge/discharge cycles were repeated. Therefore, it can be seen that the non-carbon material containing carbon material according to the present invention has a high charge/discharge capacity as well as a stable cycle life.

While the invention has been described with respect to the above specific embodiments, it should be recognized that various modifications and changes may be made and also fall within the scope of the invention as defined by the claims that follow.

Claims

What is claimed is:

1. A non-carbon material-inserted spherical carbonaceous powder comprising spherules formed from randomly agglomerated carbon thin flakes having an average size of 0.1 to 40 μm, the spherules having pores formed between the layers of the thin flakes, and a non-carbon material inserted into the pores.

2. The non-carbon material-inserted spherical carbonaceous powder of claim 1, wherein the non-carbon material is selected from the group consisting of a single metallic component, an alloy of two or more metallic components, a metal oxide or a metal nitride.

3. The non-carbon material-inserted spherical carbonaceous powder of claim 2, wherein the single metallic component is one of the elements of Groups III to V of the Periodic Table.

4. The non-carbon material-inserted spherical carbonaceous powder of claim 3, wherein the single metallic component is selected from the group consisting of silicon (Si), germanium (Ge), lead (Pb), aluminium (Al), antimony (Sb) and bismuth (Bi).

5. The non-carbon material-inserted spherical carbonaceous powder of claim 2, wherein the alloy is an alloy of the single metallic component with at least one element selected from Groups I and II metals and transition metals of the Periodic Table.

6. The non-carbon material-inserted spherical carbonaceous powder of claim 5, wherein the alloy is selected from the group consisting of Mg₂Si, CrSi₂, NiSi, Cu₆Sn₅, Sn₂Fe, SnSb, Sn₂Mn, Sn₂Co, Al₂Cu, CuSb and InSb.

7. The non-carbon material-inserted spherical carbonaceous powder of claim 2, wherein the metal oxide is a compound represented by M_xO_y, M corresponding to the single metallic component or a transition metal, and x and y are each independently a number in the range of 1 to 5.

8. The non-carbon material-inserted spherical carbonaceous powder of claim 7, wherein the metal oxide is selected from the group consisting of SiO, SiO₂, SnO, SnO₂, CoO, Co₃O₄, Fe₂O₃, NiO and NiO₂.

9. The non-carbon material-inserted spherical carbonaceous powder of claim 2, wherein the metal nitride is a compound represented by M_xN_y, Li₃__xM_xN, or Li_2x-]MN_x , M corresponding to the single metallic component or a transition metal, and x and y are each independently a number in the range of 1 to 5.

10. The non-carbon material-inserted spherical carbonaceous powder of claim 9, wherein the metal nitride is selected from the group consisting of Sn₃N₄, Ge₃N₄, Li₂₆Co₀.₄N, Li₂.₆Ni₀.₄N, Li₂₆Cu₀.₄N, Li₇MnN₄, Li₇BN₄, Li₇FeN₄, and Li₇AlN₄.

11. The non-carbon material-inserted spherical carbonaceous powder of claim 1, further comprising a coating layer of at least one material selected from a petroleum pitch, coal tar pitch and thermoplastic resin, on the surface thereof.

12. A process for preparing a non-carbon material-inserted spherical carbonaceous powder comprising the steps of mixing carbon thin flakes with a powdered or gaseous non-carbon material under a nitrogen or inert gas atmosphere, and rotatively pressurizing the resulting mixture.

13. The process of claim 12, wherein the non-carbon material is of a gaseous form, and the step of heat-treating is further conducted before or after the rotative pressurizing step.

14. The process of claim 12, which further comprises the step of pressurizing the carbon thin flakes under a nitrogen or inert gas atmosphere before mixing with the non-cabon material.

15. A process for preparing a non-carbon material-inserted spherical carbonaceous powder comprising the steps of rotatively pressurizing carbon flakes to form spherules, mixing the spherules with a gaseous non-carbon material while pressurizing under a nitrogen or inert gas atmosphere, and heat-treating the resultant.

16. The process of any one of claims 12 to 15, wherein the carbon material has an average particle size of 1 /M to 10 mm.

17. The process of claim 12, wherein the powdered non-carbon material has an average particle size of 1 nm to 1 mro.

18. The process of claim 12, wherein the powdered non-carbon material is employed in an amount of 1 to 70% by volume based on the carbon material.

19. The process of any one of claims 12 to 15, wherein the gaseous non- carbon material is a metal hydride represented by M_xH_y , M being ont of the elements of Groups III to V of the Periodic Table, and x and y being each a number in the range of 1 to 5.

20. The process of claim 19, wherein the metal hydride is selected from the group consisting of silicon hydride (SiH₄), germanium hydride (GeH₄), tin hydride (SnH₄), lead hydride (Pb₂H₂), antimony hydride (SbH₃), and bismuth hydride (BiH₃).

21. The process of any one of claims 12 to 15, wherein the gaseous non- carbon material is employed at a flow rate of 0.03 to O.lϋ/minute per 1 g of the carbon material.

22. The process of any one of claims 12 to 15, wherein the rotatively pressurizing step is carried out under the condition that generates a shear stress of 1 to 1,000 kg/cπf and a tangential velocity of 300 to 20,000 mm/sec.

23. The process of any one of claims 12 to 15, further comprising a coating step which comprises mixing the spherical carbonaceous powder with at least one coating material selected from a petroleum pitch, coal tar pitch and thermoplastic resin, rotatively pressurizing the resulting mixture, and heating and sintering the resultant at a temperature of 100 to 3,000 ^°C .

24. A lithium secondary battery comprising a non-carbon material- inserted spherical carbonaceous powder according to any one of claims 1 to 11 as a negative electrode active material.