1. A hollow silicon-based particle comprising silicon (Si) or silicon oxide (SiOx, 0

A HOLLOW SILICON-BASED PARTICLE, PREPARATION METHOD THEREOF AND ANODE ACTIVE MATERIAL FOR LITHIUM SECONDARY BATTERY INCLUDING THE SAME CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application claims the priority of Korean Patent Application No. 10-2013-0055885 filed on May 16, 2013 in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference. 10 BACKGROUND OF THE INVENTION Field of the Invention [0002] The present invention relates to a hollow silicon-based particle, a preparation method thereof and an anode active 15 material for a- lithium secondary battery including the same. Description of the Related Art [0003] Lithium secondary batteries 'recently receiving attention as power sources of portable and small electronic 20 devices is a battery using an organic electrolyte and having high energy density exhibiting higher discharge voltage by twice or more than that of a common battery using an alkaline aqueous solution. [0004] As an anode material of a lithium secondary battery, 25 graphite is widely used, however graphite has small capacity Page 1 3r-EIEX:ffX=2KZ:i2::^I2:ffiMIII2LZtE per unit weight of 372 mAh/g, and thus, the manufacture of a lithium secondary battery having high capacitance is difficult. [0005] An anode active material exhibiting higher capacitance than graphite, that is, a material (a lithium alloying material) 5 forming an alloy with ' lithium electrochemically, such as silicon, tin, an oxide thereof, etc. exhibits high capacity of greater than or equal to about 1,000 mAh/g and low charge and discharge voltage of 0.3 to 0.5 V. Thus, the material receives attention as an anode active material for a lithium secondary 10 battery. [0006] However, the above-described material has the defect of'inducing the change of a crystalline structure and increasing volume during forming an alloy withlithium electrochemically. In this case, physical contact loss may occur between electrode 15 active materials formed by coating. a powder or between an electrode active material and a current collector during charge and discharge, and the capacity decrease of a lithium secondary battery according to the progress of charge and discharge cycle may be great. 20 [0007] Therefore, for the manufacture of a lithium secondary battery having high capacity, the development of a novel silicon material that may effectively control the volume change is . required, and an anode having good capacity, efficiency, and cycle life characteristics and replaceable with a common anode 25 is necessary. Page 2 BiEi2S3:rz:E:2CBLi3Ln:2:n:s: * SUMMARY OF THE INVENTION [0008] An aspect of the present invention provides a hollow silicon-based particle producing a lithium secondary battery 5 having improved capacity properties and life characteristics by minimizing the volume expansion of the silicon-based particle.. [0009] Another aspect of the present invention provides a method for preparing the hollow silicon-based particle. 10 [0010] Another aspect of the present invention provides an anode active material and an anode including the hollow silicon-based particle. [0011] Another aspect of the present invention provides a lithium secondary battery including the anode. 15 [0012] According to an aspect of the present invention, there is provided a hollow silicon-based particle including silicon (Si) or silicon oxide (SiOx, 0 [0089] Acrylonitrile and MTC were used by 50 : 1 parts by weight, and water was used as a medium. Emulsion polymerization was 25 conducted with 0.4 g of AIBA polymerization initiator at 60 °C Page 25 ;^^prQ£2dEJ3il-I2:iEI3C2Lz_2BE:i.^—1^ for 18 hours. The product thus obtained was centrifuged to remove residual materials and obtain a polymer template of P(AN-MTC). 5 [0090] The P(AN-MTC) prepared in the above step (i) and TEOS were'mixed by the weight ratio of 1 :, 1, and 1,400 g of ethanol was mixed thereto. The mixture thus obtained was stirred at room temperature for 5 minutes under an atmospheric condition, 10 and a mixture of 34% aqueous ammonia solution and deionized water (DIW) was slowly added thereto by dropping, followed.by stirring for .3 hours at room temperature until gelatin occurred. The gelled product was dried to obtain Si02 particle coated on the surface of a polymer template. 15 [0091] The coated Si02 particle on the surface of the polymer template obtained in the above step (ii) was heat treated under an atmospheric condition at 800°C for 10 hours to remove the 20 polymer template and obtain hollow Si02 particle having a hollow core part with a diameter of 300 nm. [0092] 50 g of the hollow SiQa particle obtained in the above 25 step (iii) and 100 g of magnesium particle were mixed and heat Page 26 treated at about 650 °C for 2 hours and 30 minutes under an argon atmosphere. The reactant was stirred in a 0.1 M aqueous hydrochloric acid solution for 24 hours and filtered using a filter paper to remove MgO. The product thus obtained was dried 5 in.an oven at 80°C to obtain a hollow silicon oxide particle having a hollow core part with a diameter of 300 nm. Example 2 : Preparation of a hollow silicon oxide particle including first carbon coating layer on the inner wall thereof 10 [0093] The SiOa particle coated on the surface of the polymer template obtained in the above step (ii) was carbonized by heat treating at 700°C for 6 hours under an argon atmosphere. As a result, Si02 particle having a hollow core part with a diameter 15 of 300 nm and including a first carbon coating layer on the inner wall thereof was obtained. [0094] 50 g of the hollow Si02 particle including the first 20 carbon coating layer on the inner wall thereof and obtained in the above step (iii) and 100 g of magnesium particle were mixed and heat treated at about 650°C for about 2 hours and 30 minutes under an argon atmosphere. The reactant was stirred in a 0.1 M aqueous hydrochloric acid solution for 24 hours and filtered 25 using a filter paper to remove MgO. The product thus obtained Page 27 . was dried in an oven at 80°C to obtain a hollow silicon oxide particle including the first carbon coating layer on the inner wall of a hollow core part with a diameter of 300 nm. 5 Example 3: Manufacture of anode and lithium secondary battery Manufacture of anode [0095] The hollow silicon particle obtained in Example 1 as an anode active material, super-P as a conductive agent, and PVdF as a binder were mixed by the weight ratio of 80 : 10. : 10 10 to prepare a homogeneous anode active material composition. [0096] The anode active material composition thus obtained was coated on one side of a copper collector to a thickness of 65 jam, dried, compressed and punched to , a certain size to manufacture an anode. 15 Manufacture of lithium secondary battery [0097] In a nonaqueous electrolyte solvent obtained by mixing ethylene carbonate and diethyl carbonate by the volume ratio of 30 : 70, LiPFg was added to prepare a 1 M LiPFg nonaqueous 20 electrolyte. [0098] A lithium metal foil was used as a counter electrode, and a polyolef in separator was disposed between two electrodes . Then, the electrolyte was injected to manufacture a coin type half cell. 25 Page 2 8 :ij [EE:iiriii2KE:i:z:^ZBfci3rzi:2.j^jLm. Example 4,: Manufacture of anode and lithium secondary battery [0099] A coin type half cell was manufactured by conducting the same procedure described in Example 3 except for using the hollow silicon particle including the first carbon coating 5 layer formed on the inner wall thereof, and manufactured in Example 2 as an anode active material. Comparative Example 1 , [00100] A coin type half cell was manufactured by conducting 10 the same procedure described in Example 3 except for using silicon particle (Sigma-Aldrich) as an anode active material. Experimental Example 1 15 [00101] The products obtained in steps i) and ii) in Example 1, and the silicon particle obtained in Examples 1 and 2 were observed through SEM micro photographic images, and the results are illustrated in FIGS. 5 and 6. [00102] In FIG. 5, 1) is a SEM photographic image of the 20 surface of the P(AN-MTC) polymer template obtained in step i) of Example 1, and 2) is a SEM photographic image of the surface of Si02 particle coated on the surface of the P(AN-MTC) obtained in step ii) of Example 1. [00103] As shown in FIG. 5, it may be secured that spherical 25 polymer particle without hollow were formed. Page 29 :i^iHr:ffiEEEEi:2EH:]t2CH:2303L WT^Z [00104] In FIG. 6, 1) is a SEM photographic image'of the cross section of the hollow silicon oxide particle obtained in Example 1, and 2) is a SEM photographic image of the cross section of the hollow silicon oxide particle including a first carbon 5 coating layer on the inner wall thereof obtained in Example 2. [00105] • As shown in FIG. 6, it may be secured that hollow was formed in the silicon particle different from the SEM photographic image of FIG. 5. 10 Experimental Example 2 [00106] The amount carbon was measured by using a carbon/sulfur amount analyzer (C/S analyzer) for each of the hollow silicon oxide particle obtained in Examples 1 and 2. 15 [00107] As a result, the amount of carbon in the hollow silicon oxide particle obtained in Example 1 was about 2 wt% with respect to the total amount of the hollow silicon particle, and the amount of carbon in.the hollow silicon oxide particle including the first carbon coating layer was about 25 wt% with 20 ' respect to the total amount of the hollow silicon particle. Experimental Example 3 [00108] To examine the capacity with respect to' voltage 25 level (V) and the capacity with respect to charge and discharge Page 30 :ZELMZBIElSlZI2SZ:r2-^2IEI3^1.2^Ee- ^ cycle of the coin type half cell manufactured in Example 3, the coin type half cell manufactured in Example 3 was charged at 23°C with constant current (CC) conditions at 1.5 V with 0.1 C, and discharged with CC conditions at 0.005 V with 0.1 C, and 5 capacity was measured. This procedure was repeated by 1 to 49 cycles. The results are shown- in FIG. 7. [00109] As shown in FIG. 7, it may be secured, that the coin type half cell manufactured in Example 3 of the present invention generates no charge change from 1^*^ to 49^*^ cycles. 10 . Since the most serious factor affecting the cycle properties is volume expansion, the defects concerning the volume expansion may be expected to be improved. On the contrary, for Comparative Example 1, the capacity is greatly decreased from 0*^*^ to 5*^"^ cycles, and about 3.5 times or more'capacity was shown 15 from 49*^"^ cycle when compared to the result of Example 3. [00110] While the present invention has been shown and described in connection with the exemplary embodiments, it will beapparent to those skilled in the art that modifications and variations can be made without departing from the spirit and 20 scope of the invention as defined by the appended claims. WE CLAIM:- 1. A hollow silicon-based particle comprising silicon (Si) or silicon oxide (SiOx, 0