Negative electrode active material for secondary batteries, method for manufacturing the same, and secondary battery containing the same

Abstract

The present invention provides a negative electrode active material for secondary batteries that suppresses volume changes that occur during repeated charging and discharging and exhibits excellent electrochemical properties, a method for producing the same, and a secondary battery containing the same. [Solution] The negative electrode active material for the secondary battery contains silicon (Si)-based particles, and the silicon (Si)-based particles contain MO-Si bonds (where M is a metal).

Description

[Technical Field]

[0001] This invention relates to a negative electrode active material for a secondary battery, a method for producing the same, and a secondary battery containing the same. [Background technology]

[0002] In the field of lithium-ion secondary batteries, silicon anode materials are attracting attention as next-generation battery anode materials because their theoretical capacity per unit weight is more than 10 times that of commercially available graphite materials (370 mAh / g).

[0003] However, during charging, the volume increases by more than 300% through the reaction between lithium ions and silicon. This means that when charging and discharging are repeated, the large volume change can cause the silicon to crack and separate from the electrodes. [Overview of the project] [Problems that the invention aims to solve]

[0004] One example is the provision of a negative electrode active material for secondary batteries that suppresses volume changes that occur during repeated charging and discharging and exhibits excellent electrochemical properties.

[0005] Another embodiment provides a method for manufacturing the negative electrode active material for the secondary battery.

[0006] Another embodiment provides a secondary battery containing the negative electrode active material for the secondary battery. [Means for solving the problem]

[0007] One embodiment provides a negative electrode active material for a secondary battery, which includes silicon (Si)-based particles, wherein the silicon (Si)-based particles contain MO-Si bonds (where M is a metal).

[0008] The aforementioned metal (M) may include B, P, Ge, Ti, Zr, or a combination thereof.

[0009] The silicon (Si) particles may further contain Si-Si bonds.

[0010] The silicon (Si) particles can be produced by reducing waste glass containing silica and metal oxides at a temperature of 200°C to 350°C.

[0011] The aforementioned silicon (Si) particles exhibit a 800 cm⁻¹ spectrum in the Fourier transform infrared (FT-IR) spectrum. -1 ~900cm -1 Wave number: 650cm -1 ~750cm -1 A peak in transmittance corresponding to the MO-Si bond can be shown at the wavenumber, or a combination thereof.

[0012] The average particle size of the silicon (Si) particles may be between 0.05 μm and 5 μm.

[0013] Another embodiment provides a method for producing a negative electrode active material for a secondary battery, which includes the step of reducing waste glass containing silica and metal oxides at a temperature of 200°C to 350°C to produce silicon (Si)-based particles, wherein the produced silicon (Si)-based particles contain MO-Si bonds (where M is a metal).

[0014] The aforementioned waste glass may be heat-tempered glass generated during the disposal of displays.

[0015] The metal oxide and the metal (M) may include B, P, Ge, Ti, Zr, or combinations thereof.

[0016] The reduction may be carried out by adding a reducing agent containing Al, AlCl3, Zn, Mg, Ca, or a combination thereof.

[0017] Another embodiment provides a secondary battery comprising a negative electrode containing the negative electrode active material; a positive electrode; and an electrolyte.

[0018] The capacity of the negative electrode can be 800 mAh / g to 1700 mAh / g at 1C.

[0019] The negative electrode can have a volume change of 5% to 40% after repeating charge and discharge at 0.5C for 50 cycles.

Effect of the Invention

[0020] The negative electrode active material for a secondary battery according to one embodiment can not only improve the electrochemical characteristics of the secondary battery by suppressing the volume change that occurs when repeating charge and discharge, but also recycle waste glass from various displays, which is environmentally friendly.

Brief Description of the Drawings

[0021] [Figure 1a] They are scanning electron microscope (SEM) images of the negative electrode active material for a secondary battery according to Example 1 and Comparative Example 1, respectively. [Figure 1b] They are scanning electron microscope (SEM) images of the negative electrode active material for a secondary battery according to Example 1 and Comparative Example 1, respectively. [Figure 2a] They are X-ray diffraction analysis (XRD) graphs of the negative electrode active material for a secondary battery according to Example 1 and Comparative Example 1, respectively. [Figure 2b] They are X-ray diffraction analysis (XRD) graphs of the negative electrode active material for a secondary battery according to Example 1 and Comparative Example 1, respectively. [Figure 3a] They are graphs showing Fourier transform infrared (FT-IR) spectra of the negative electrode active material for a secondary battery according to Example 1 and Comparative Example , respectively. [Figure 3b] They are graphs showing Fourier transform infrared (FT-IR) spectra of the negative electrode active material for a secondary battery according to Example 1 and Comparative Example 1, respectively. [Figure 4a] They are graphs showing the changes in voltage and discharge capacity according to the initial charge and discharge cycles in the secondary batteries according to Example 1 and Comparative Example 1, respectively. [Figure 4b]These graphs show the changes in voltage and discharge capacity during the initial charge-discharge cycle for the secondary batteries according to Example 1 and Comparative Example 1, respectively. [Figure 5a] These graphs show the capacity change due to repeated charge-discharge cycles in the secondary batteries according to Example 1 and Comparative Example 1, respectively. [Figure 5b] These graphs show the capacity change due to repeated charge-discharge cycles in the secondary batteries according to Example 1 and Comparative Example 1, respectively. [Figure 6a] These images show the volume change of the negative electrode when the secondary batteries of Example 1 and Comparative Example 1 undergo repeated charging and discharging. [Figure 6b] These images show the volume change of the negative electrode when the secondary batteries of Example 1 and Comparative Example 1 undergo repeated charging and discharging. [Modes for carrying out the invention]

[0022] The following provides a detailed explanation of each implementation example, designed to be easily implemented by someone with ordinary technical knowledge. However, each implementation example can be realized in various different forms and is not limited to those described herein.

[0023] In one embodiment, the negative electrode active material for a secondary battery contains silicon (Si)-based particles, in which the silicon (Si)-based particles contain MO-Si bonds (where M is a metal).

[0024] In one example, silicon (Si) particles used as the negative electrode active material contain MO-Si bonds, which allows for control of the volume change of silicon (Si) generated during reaction with lithium ions. In other words, by using silicon (Si) containing MO-Si bonds as the negative electrode active material, the volume change of silicon generated during repeated charging and discharging can be suppressed, thereby improving the electrochemical properties of the secondary battery.

[0025] Specifically, the M-O-Si bond can be a particle having an M-O-Si bond. In other words, the silicon (Si)-based particles may be in a form in which a large number of particles are aggregated, and may include a particle having an M-O-Si bond as one of the large number of particles.

[0026] In the M-O-Si bond, the metal (M) can include B, P, Ge, Ti, Zr, or a combination thereof.

[0027] The silicon (Si)-based particles according to one embodiment have not only a pure Si-Si bond but also the M-O-Si bond. Specifically, according to X-ray diffraction analysis (XRD) and Fourier transform infrared (FT-IR) spectrum of the silicon (Si)-based particles, they include a pure Si-Si bond and additionally have an M-O-Si bond. Here, the Si-Si bond can be a particle having a Si-Si bond.

[0028] More specifically, the silicon (Si)-based particles have, in the Fourier transform infrared (FT-IR) spectrum, a transmittance peak corresponding to the M-O-Si bond at a wave number of 800 cm -1 to 900 cm -1 , a wave number of 650 cm -1 to 750 cm -1 , or a combination of these wave numbers. The transmittance peak corresponding to the M-O-Si bond can be shown, for example, at a wave number of 850 cm -1 to 900 cm -1 , a wave number of 650 cm -1 to 700 cm -1 , or a combination of these wave numbers.

[0029] The average particle size of the silicon (Si)-based particles can be 0.05 μm to 5 μm, for example, 0.05 μm to 1 μm, 0.1 μm to 0.8 μm. When the average particle size of the silicon (Si)-based particles is within the above range, a high-capacity electrode can be obtained.

[0030] The silicon (Si) particles can be produced by a low-temperature reduction method using waste glass containing silica and metal oxides.

[0031] The aforementioned waste glass may be heat-strengthened glass used in LCD displays for smartphones and other devices. Currently, most waste glass generated during the disposal of various displays is not recycled and is instead landfilled, contributing to environmental pollution. In one example, using the aforementioned waste glass as a raw material for the negative electrode active material allows for the recycling of waste glass from various displays, thereby reducing environmental pollution and making it environmentally friendly.

[0032] Furthermore, the conventional process of manufacturing silicon from silica requires temperatures of 1700°C or higher when using a carbothermal process, and when using metal reducing agents such as magnesium or aluminum, the exothermic reaction at temperatures of 2500°C or higher makes it difficult to control the structure. On the other hand, one example involves using waste glass, which eliminates the need for high-temperature equipment, thus significantly reducing raw material costs, as well as enabling low-temperature reduction. The law makes it easier to control the structure, enabling the production of high-purity silicon.

[0033] Specifically, silicon (Si) particles according to one example can be manufactured by reducing waste glass containing silica and metal oxides at temperatures of 200°C to 350°C, for example, 200°C to 300°C or 200°C to 280°C.

[0034] When manufactured at a low reduction temperature within the aforementioned range, the structure can be easily controlled, and high-purity silicon-based particles can be obtained. Furthermore, since the manufactured silicon-based particles contain MO-Si bonds, volume changes of silicon (Si) that occur during charging and discharging can be prevented.

[0035] The metal in the aforementioned metal oxide is the same as the metal (M) in the MO-Si bond. For example, the metal oxide may include boron oxide, phosphorus oxide, germanium oxide, titanium oxide, zirconium oxide, or a combination thereof.

[0036] The silicon (Si) particles may be produced by adding a reducing agent. The reducing agent may include Al, AlCl3, Zn, Mg, Ca, or a combination thereof. For example, both Al and AlCl3 can be used as reducing agents, in which case they can be mixed and used in a weight ratio of 1:5 to 1:20, for example, 1:10 to 1:20.

[0037] The following explanation applies to secondary batteries containing the negative electrode active material described above.

[0038] The secondary battery includes a negative electrode, a positive electrode, and an electrolyte.

[0039] A negative electrode using silicon (Si)-based particles as the negative electrode active material, according to one embodiment, can have a high capacity, specifically 800 mAh / g to 1700 mAh / g at 1C, for example, 800 mAh / g to 1500 mAh / g at 1C, or 900 mAh / g to 1200 mAh / g at 1C.

[0040] A negative electrode using silicon (Si)-based particles as the negative electrode active material, as described in one embodiment, can suppress volume changes that occur when charging and discharging is repeated. Specifically, the volume change after 50 charge-discharge cycles at 0.5C may be 5% to 40%, for example, 5% to 20% or 10% to 18%.

[0041] The negative electrode includes a current collector and a negative electrode active material layer located on the current collector.

[0042] The current collector can be, but is not limited to, copper foil, nickel foil, stainless steel foil, titanium foil, nickel foam, copper foam, a polymer substrate coated with a conductive metal, or a combination thereof.

[0043] The negative electrode active material layer includes the negative electrode active material described above, and may further include a binder and a conductive material.

[0044] The binder plays a role in ensuring that each negative electrode active material particle adheres well to each other, and also in ensuring that the negative electrode active material adheres well to the negative electrode current collector. Typical examples of such binders include polyvinyl alcohol, carboxymethylcellulose, hydroxypropylcellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylic styrene-butadiene rubber, epoxy resin, nylon, and the like. However, this is not the only example.

[0045] The conductive material is used to impart conductivity to the electrodes, and any electronically conductive material that does not cause chemical changes in the battery can be used. Examples include carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjenblack, and carbon fibers; metallic materials such as metal powders or metal fibers of copper, nickel, aluminum, and silver; conductive polymers such as polyphenylene derivatives; or conductive materials containing mixtures thereof.

[0046] The positive electrode includes a current collector and a positive electrode active material layer located on the current collector.

[0047] Aluminum can be used as the current collector, but it is not limited to this.

[0048] The positive electrode active material layer contains a positive electrode active material. As the positive electrode active material, a compound capable of reversible intercalation and deintercalation of lithium (lithium intercalation compound), specifically a lithium metal oxide, can be used. Specifically, as the lithium oxide, an oxide containing at least one metal selected from cobalt, manganese, nickel, and aluminum, and lithium can be used.

[0049] The positive electrode active material layer may further include a binder and a conductive material.

[0050] The binder plays a role in ensuring that each positive electrode active material particle adheres well to each other, and that the positive electrode active material adheres well to the positive electrode current collector. Typical examples of binders that can be used include, but are not limited to, polyvinyl alcohol, carboxymethylcellulose, hydroxypropylcellulose, polyvinyl chloride, carboxylated polyvinyl chloride, polyvinyl fluoride, polymers containing ethylene oxide, polyvinylpyrrolidone, polyurethane, polytetrafluoroethylene, polyvinylidene fluoride, polyethylene, polypropylene, styrene-butadiene rubber, acrylic styrene-butadiene rubber, epoxy resin, and nylon.

[0051] The conductive material is used to impart conductivity to the electrodes, and any electronically conductive material that does not cause chemical changes in the battery can be used. Examples include carbon-based materials such as natural graphite, artificial graphite, carbon black, acetylene black, Ketjenblack, and carbon fibers; metallic materials such as metal powders or metal fibers of copper, nickel, aluminum, and silver; conductive polymers such as polyphenylene derivatives; or conductive materials containing mixtures thereof.

[0052] The negative electrode and positive electrode are manufactured by preparing an active material composition by mixing an active material, a conductive material, and a binder in a solvent, and then applying this composition to a current collector. Since such electrode manufacturing methods are widely known in the art, they are omitted from the detailed description herein. The solvent can be, but is not limited to, N-methylpyrrolidone.

[0053] The electrolyte comprises a lithium salt and an organic solvent.

[0054] The aforementioned lithium salt is a substance that dissolves in an organic solvent and acts as a source of lithium ions in a secondary battery, enabling the basic operation of the secondary battery and promoting the movement of lithium ions between the positive and negative electrodes.

[0055] Typical examples of the aforementioned lithium salts include LiPF6, LiBF4, LiSbF6, LiAsF6, LiN(SO3C2F5)2, LiN(CF3SO2)2, LiC4F9SO3, LiClO4, LiAlO2, LiAlCl4, and LiN(C x F 2x+1 SO2)(C y F 2y+1 Examples include SO2) (where x and y are natural numbers), LiCl, LiI, LiB(C2O4)2 (lithium bis(oxalato)borate (LiBOB)), or combinations thereof.

[0056] The concentration of the lithium salt may be in the range of about 0.1 M to about 2.0 M. When the concentration of the lithium salt falls within this range, the gel-like electrolyte composition has appropriate conductivity and viscosity, so it can exhibit excellent electrolyte performance and lithium ions can move effectively.

[0057] The organic solvent acts as a medium through which the ions involved in the electrochemical reaction of the secondary battery can move. The organic solvent is a non-aqueous organic solvent and can be selected from carbonate solvents, ester solvents, ether solvents, ketone solvents, alcohol solvents, and aprotic solvents.

[0058] Examples of the carbonate-based solvent include dimethyl carbonate (dimethyl carbonate). Carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), methyl propyl carbonate (MPC), ethyl propyl carbonate (EPC), ethyl methyl carbonate (EMC), ethylene carbonate (EC), propylene carbonate (PC), butylene carbonate (BC), etc. may be used.

[0059] In particular, when using a mixture of a linear carbonate compound and a cyclic carbonate compound, it is preferable because it can increase the dielectric constant while simultaneously producing a solvent with low viscosity. In this case, the cyclic carbonate compound and the linear carbonate compound can be mixed and used in a volume ratio of about 1:1 to 1:9.

[0060] Furthermore, as the ester-based solvent, for example, methyl acetate, ethyl acetate, n-propyl acetate, dimethyl acetate, methyl propionate, ethyl propionate, γ-butyrolactone, decanolide, valerolactone, mevalonolactone, and caprolactone may be used. As the ether-based solvent, for example, dibutyl ether, tetraglyceride, diglyme, dimethoxyethane, 2-methyltetrahydrofuran, and tetrahydrofuran may be used. As the ketone-based solvent, cyclohexanone may be used. Furthermore, as the alcohol-based solvent, ethyl alcohol and isopropyl alcohol may be used.

[0061] The aforementioned organic solvents can be used individually or in combination of one or more, and the mixing ratio when using a mixture of one or more can be appropriately adjusted depending on the performance of the battery to be used.

[0062] Depending on the type of secondary battery, a separator may be present between the positive and negative electrodes. Suitable separators include polyethylene, polypropylene, polyvinylidene fluoride, or multilayer films of two or more layers thereof. It goes without saying that mixed multilayer films such as layer separators, polyethylene / polypropylene / polyethylene 3-layer separators, and polypropylene / polyethylene / polypropylene 3-layer separators can be used. [Examples]

[0063] The following describes specific embodiments of the present invention. However, the embodiments described below are merely illustrative or explanatory of the present invention and should not be limited thereto. Furthermore, any matters not described herein can be sufficiently inferred by technical analogy by those skilled in this art, and therefore their explanation is omitted.

[0064] (Manufacturing of silicon-based particles)

[0065] Example 1

[0066] Silicon (Si) particles were produced using a low-temperature reduction method with borosilicate glass (neutral borosilicate glass 5.1, USP and EP Type 1 glass) (containing 85% SiO2, 13% B2O3, and 2% Na), which is waste glass generated from the disposal of smartphones, and the reducing agents Al and AlCl3. Specifically, the borosilicate glass, Al, and AlCl3 were mixed in a weight ratio of 1:0.8:8 and then placed in a stainless steel reactor (Unilok Corporation). The reaction was carried out in an argon atmosphere at 250°C for 15 hours to produce silicon particles. After that, impurities were removed by chemical etching with an HCl solution.

[0067] Comparative Example 1

[0068] Pure silica (bare silica) (SiO2 99.5%, 400 mesh, 2 micron APS powder, SA surface area 2 m²) 2 Silicon-based particles were produced by mixing ( / g) with Al and AlCl3 in a weight ratio of 1:0.8:8 and then placing the mixture in a stainless steel reactor (Unilok Corporation) and reacting it under an argon atmosphere at 250°C for 15 hours. Subsequently, impurities were removed by chemical etching with an HCl solution.

[0069] (Manufacturing of negative electrodes for secondary batteries) Silicon-based particles produced in Example 1 and Comparative Example 1 were used as negative electrode active materials. Carbon black was added as a conductive material, and polyacrylic acid (PAA) was added as a binder in a weight ratio of 60:20:20 to water, which was used as the solvent, to produce negative electrode mixture slurries (solid content: 50% by weight). The negative electrode mixture slurry was then applied to a 20 μm thick copper (Cu) thin film, which served as a negative electrode current collector, and dried to produce the respective negative electrodes.

[0070] Evaluation 1: Scanning electron microscope (SEM) measurement of the negative electrode active material Scanning electron microscope (SEM) measurements were performed on the surface of silicon-based particles produced in Example 1 and Comparative Example 1 as negative electrode active materials, and the results are shown in Figures 1a and 1b.

[0071] Figures 1a and 1b are scanning electron microscope (SEM) images of the negative electrode active material for secondary batteries according to Example 1 and Comparative Example 1, respectively.

[0072] Referring to Figures 1a and 1b, it can be confirmed that in Example 1, silicon-based particles having a size of 1 micrometer or less were produced. Also, in Comparative Example 1... In this case, silicon-based particles having a size of 1 micrometer or less can be manufactured, and it can be confirmed that the surface is smooth.

[0073] Evaluation 2: X-ray diffraction (XRD) analysis of the negative electrode active material X-ray diffraction (XRD) analysis was performed on the silicon-based particles produced in Example 1 and Comparative Example 1 as the negative electrode active material, and the results are shown in Figures 2a and 2b.

[0074] Figures 2a and 2b are X-ray diffraction (XRD) graphs of the negative electrode active materials for secondary batteries according to Example 1 and Comparative Example 1, respectively.

[0075] Referring to Figures 2a and 2b, it can be seen that in the case of silicon-based particles produced in Example 1, pure silicon (Si) particles were synthesized within the silicon-based particles, whereas in the case of silicon-based particles produced in Comparative Example 1, it can be seen that unreacted silica (SiO2) particles still exist even after etching with HCl. This indicates that the silicon-based particles in this embodiment are particles with high silicon (Si) purity, even while containing MO-Si bonds.

[0076] Evaluation 3: Fourier transform infrared (FT-IR) measurement of negative electrode active material Fourier transform infrared (FT-IR) measurements were performed on silicon-based particles produced in Example 1 and Comparative Example 1 as negative electrode active materials, and the results are shown in Figures 3a and 3b.

[0077] Figures 3a and 3b are graphs showing the Fourier transform infrared (FT-IR) spectra of the negative electrode active materials for secondary batteries according to Example 1 and Comparative Example 1, respectively.

[0078] Referring to Figures 3a and 3b, it can be confirmed that the silicon-based particles produced in Example 1 contain pure Si-Si bonds and additionally possess BO-Si and Si-O-Si bonds. On the other hand, it can be confirmed that the silicon-based particles produced in Comparative Example 1 only contain Si-O-Si and Si-Si bonds due to residual silica. This indicates that the silicon-based particles in one embodiment contain MO-Si bonds.

[0079] Evaluation 4: Measurement of the electrochemical properties of secondary batteries Half-cells were fabricated using the negative electrode and Li counter electrode manufactured in Example 1 and Comparative Example 1. Initial charge-discharge cycles were performed on the half-cells at 0.05C, and the resulting discharge capacities are shown in Figures 4a and 4b.

[0080] Figures 4a and 4b are graphs showing the changes in voltage and discharge capacity due to the initial charge-discharge cycle in the secondary batteries according to Example 1 and Comparative Example 1, respectively.

[0081] Referring to Figures 4a and 4b, it was confirmed that the discharge capacity in Example 1 was approximately 1500 mAh / g, and in Comparative Example 1, the discharge capacity was approximately 1800 mAh / g.

[0082] Next, after performing initial charge-discharge cycles, a long-term life test was conducted using a 1C fast charge-discharge experiment. The results are shown in Figures 5a and 5b.

[0083] Figures 5a and 5b are graphs showing the capacity change due to repeated charge-discharge cycles in the secondary batteries according to Example 1 and Comparative Example 1, respectively.

[0084] Referring to Figures 5a and 5b, in Example 1, a capacity of approximately 1000 mAh / g is maintained up to 200 cycles, while in Comparative Example 1, almost no capacity is maintained after 100 cycles. It can be confirmed that the quantity is not realized. In other words, it can be seen that Comparative Example 1 could not withstand the volume change that occurs when charging and discharging is repeated, and its capacity decreased.

[0085] This demonstrates that, as shown in one example, when silicon-based particles containing MO-Si bonds are used as the negative electrode active material, the volume change of the negative electrode is suppressed and the electrochemical properties are improved.

[0086] Evaluation 5: Measurement of volume change of the negative electrode Half-cells were fabricated using the negative electrode and Li counter electrode manufactured according to Example 1 and Comparative Example 1. An initial charge-discharge cycle was performed on the half-cell at 0.05C, and after repeating the charge-discharge cycle 50 times at a rate of 0.5C, the volume change of the negative electrode was measured, and the results are shown in Figures 6a and 6b.

[0087] Figures 6a and 6b are images illustrating the volume change of the negative electrode when the secondary battery according to Example 1 and Comparative Example 1 undergoes repeated charging and discharging, respectively.

[0088] Referring to Figures 6a and 6b, it can be seen that in Example 1, the volume expanded by approximately 16%, while in Comparative Example 1, the volume expanded by approximately 225%. In other words, it can be seen that in Comparative Example 1, the volume change is not controlled by repeated charging and discharging.

[0089] This demonstrates that, as shown in one example, when silicon-based particles containing MO-Si bonds are used as the negative electrode active material, the volume change of the negative electrode is suppressed.

[0090] Although preferred embodiments of the present invention have been described above, the present invention is not limited thereto, and can be implemented in various ways within the scope of the claims, detailed description of the invention, and accompanying drawings, and these also naturally fall within the scope of the present invention.

Claims

1. Contains silicon (Si) particles, The silicon (Si)-based particles contain M-O-Si bonds (where M is a metal), and this is an active material for a negative electrode in a secondary battery.

2. The negative electrode active material for a secondary battery according to claim 1, wherein the metal (M) includes B, P, Ge, Ti, Zr, or a combination thereof.

3. The negative electrode active material for a secondary battery according to claim 1, wherein the silicon (Si) particles further contain Si-Si bonds.

4. The silicon (Si)-based particles are produced by reducing waste glass containing silica and metal oxides at a temperature of 200°C to 350°C, as described in claim 1, for a negative electrode active material for a secondary battery.

5. The silicon (Si) particles exhibit a Fourier transform infrared (FT-IR) spectrum of 800 cm⁻¹. －１ ~900cm －１ Wave frequency, 650 cm －１ ~750cm －１ The negative electrode active material for a secondary battery according to claim 1, which exhibits a peak in transmittance corresponding to the M-O-Si bond at the wavenumber, or a combination thereof.

6. The negative electrode active material for a secondary battery according to claim 1, wherein the average particle size of the silicon (Si)-based particles is 0.05 μm to 5 μm.

7. The process includes the step of reducing waste glass containing silica and metal oxides at a temperature of 200°C to 350°C to produce silicon (Si) particles. A method for producing a negative electrode active material for a secondary battery, wherein the manufactured silicon (Si) particles contain M-O-Si bonds (where M is a metal).

8. The method for producing a negative electrode active material for a secondary battery according to claim 7, wherein the waste glass is heat-strengthened glass generated when a display is discarded.

9. The method for producing a negative electrode active material for a secondary battery according to claim 7, wherein the metal of the metal oxide and the metal (M) include B, P, Ge, Ti, Zr, or a combination thereof.

10. The aforementioned reduction involves Al, AlCl ３ A method for producing a negative electrode active material for a secondary battery according to claim 7, wherein the method is carried out by adding a reducing agent containing Zn, Mg, Ca, or a combination thereof.

11. A negative electrode comprising the negative electrode active material according to any one of claims 1, 2, and 4 to 6; Positive electrode; and A secondary battery containing an electrolyte.

12. The secondary battery according to claim 11, wherein the capacity of the negative electrode is 800 mAh / g to 1700 mAh / g at 1C.

13. The secondary battery according to claim 11, wherein the negative electrode has a volume change of 5% to 40% after repeated charging and discharging cycles at 0.5C.

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