WO2023210867A1 - Silicon anode material, having boron oxide applied thereto, for lithium ion secondary battery - Google Patents

Silicon anode material, having boron oxide applied thereto, for lithium ion secondary battery Download PDF

Info

Publication number
WO2023210867A1
WO2023210867A1 PCT/KR2022/009191 KR2022009191W WO2023210867A1 WO 2023210867 A1 WO2023210867 A1 WO 2023210867A1 KR 2022009191 W KR2022009191 W KR 2022009191W WO 2023210867 A1 WO2023210867 A1 WO 2023210867A1
Authority
WO
WIPO (PCT)
Prior art keywords
plate
shaped silicon
boron oxide
silicon
ion secondary
Prior art date
Application number
PCT/KR2022/009191
Other languages
French (fr)
Korean (ko)
Inventor
전관구
Original Assignee
주식회사 이큐브머티리얼즈
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by 주식회사 이큐브머티리얼즈 filed Critical 주식회사 이큐브머티리얼즈
Publication of WO2023210867A1 publication Critical patent/WO2023210867A1/en

Links

Images

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/052—Li-accumulators
    • H01M10/0525—Rocking-chair batteries, i.e. batteries with lithium insertion or intercalation in both electrodes; Lithium-ion batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/38—Selection of substances as active materials, active masses, active liquids of elements or alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/48—Selection of substances as active materials, active masses, active liquids of inorganic oxides or hydroxides
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/36—Selection of substances as active materials, active masses, active liquids
    • H01M4/58—Selection of substances as active materials, active masses, active liquids of inorganic compounds other than oxides or hydroxides, e.g. sulfides, selenides, tellurides, halogenides or LiCoFy; of polyanionic structures, e.g. phosphates, silicates or borates
    • H01M4/583—Carbonaceous material, e.g. graphite-intercalation compounds or CFx
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries

Definitions

  • the present invention relates to a silicon anode material for lithium-ion secondary batteries to which boron oxide is applied. More specifically, by using plate-shaped silicon formed from a waste silicon kerf, not only is the unit cost low, but the initial capacity and lifespan are improved by applying boron oxide. This relates to a silicon anode material for lithium-ion secondary batteries using boron oxide with improved performance.
  • graphite has been used as the negative electrode active material for lithium-ion secondary batteries.
  • Graphite has a theoretical capacity of 372 mAh/g of lithium ion charging capacity, and in reality, it is a material with a capacity of 360 mAh/g and has a layered structure, with a mechanism in which lithium is inserted between layers and charged.
  • silicon is a lithium ion storage material for anode materials that has a larger capacity than graphite.
  • Silicon is a material with a theoretical capacity of 4200mAh/g.
  • four lithium ions are combined with one silicon, causing the volume to expand more than three times.
  • Silicon, which has expanded in volume cannot return to its original state when lithium escapes, cracks occur, and is separated into fine nanoparticles, many of which are electrically disconnected from the electrolyte or electrolyte solution, making it impossible to recharge lithium.
  • silicon anode active material has a short charge/discharge life and has not been used as an anode active material to replace graphite.
  • Silicon used as a negative electrode active material is mainly made of metallic silicon with a purity of 99.9% or higher. Since it was discovered that cracks caused by lithium charging and discharging are reduced when nano-sized silicon is used, much effort has been made to create nano-silicon.
  • waste silicon kerf (silicon kerf) generated in the process of cutting a lump of metal silicon into thin pieces to obtain a silicon wafer in the solar cell industry or semiconductor industry is used.
  • the waste silicon cuff is high-purity silicon with a purity of 99.9999999% to 99.999999999% used in the solar cell industry or semiconductor industry, and by using a wire-shaped saw, it comes off as a nano-thick plate-shaped material.
  • Such high-purity plate-shaped silicon is a good candidate for anode active material for lithium secondary batteries.
  • the present invention uses plate-shaped silicon formed from waste silicon kerf to not only lower the unit price but also apply boron oxide to improve initial capacity and life performance by applying boron oxide lithium ion secondary.
  • the purpose is to provide silicon anode materials for batteries.
  • the silicon anode material for a lithium-ion secondary battery to which boron oxide is applied includes a plate-shaped silicon composite made of plate-shaped silicon formed from a waste silicon kerf, wherein the plate-shaped The silicon composite includes plate-shaped silicon particles having an apparent density of 0.1 to 0.4 g/cm3 formed by pulverizing the plate-shaped silicon; An oxide film formed by oxidizing the surface of the plate-shaped silicon particles; Boron oxide is applied, including a boron oxide coating film formed by coating boron oxide on the surface of the plate-shaped silicon particle on which the oxide film is formed, and a carbon coating film formed by coating the outer shell of the plate-shaped silicon particle with conductive carbon to surround the oxide film and the boron oxide coating film.
  • a silicon anode material for lithium ion secondary batteries can be provided.
  • the plate-shaped silicon particles are characterized in that they are obtained by wet milling and drying plate-shaped silicon.
  • the plate-shaped silicon is characterized by an average thickness of 10 to 100 nm and an average length of 10 ⁇ m or less.
  • the oxide film is characterized by an average thickness of 2 to 10 nm.
  • the oxide film is formed by adding an oxidizing agent to the plate-shaped silicon particles and heating them to 700 to 1,100°C.
  • the boron oxide coating film is characterized in that it is formed by adding an aqueous boric acid solution to the plate-shaped silicon particles on which the oxide film is formed and heating it to 550 to 700 ° C.
  • the carbon coating film is characterized by an average thickness of 3 to 20 nm.
  • the carbon coating film is characterized in that it is formed by selectively adding one of hydrocarbon gas, liquefied natural gas, and liquefied petroleum gas to the plate-shaped silicon particles on which the oxide film and boron oxide coating film are formed, and thermally decomposing it at 750 to 1000 ° C.
  • the unit cost of the silicon anode material for a lithium-ion secondary battery to which boron oxide is applied according to the embodiment of the present invention as described above can be reduced by using plate-shaped silicon formed from a waste silicon kerf.
  • Figure 1 is an exemplary diagram showing the appearance of a plate-shaped silicon composite of a silicon anode material for a lithium ion secondary battery to which boron oxide is applied according to an embodiment of the present invention.
  • Figure 2 is an SEM photograph of plate-shaped silicon used in the production of a silicon anode material for a lithium-ion secondary battery to which boron oxide is applied according to an embodiment of the present invention.
  • Figure 3 is an example diagram showing the appearance of the plate-shaped silicon of Figure 2.
  • Figure 4 is an exemplary diagram showing the appearance of plate-shaped silicon particles of a silicon anode material for a lithium ion secondary battery to which boron oxide is applied according to an embodiment of the present invention.
  • Figure 5 is an example diagram showing an oxide film formed on the plate-shaped silicon particle of Figure 4.
  • FIGS. 6A and 6B are TEM photographs of the plate-shaped silicon particles on which the oxide film of FIG. 5 is formed.
  • Figure 7 is an exemplary diagram showing a boron oxide coating film formed on the plate-shaped silicon particle on which the oxide film of Figure 5 is formed.
  • Figure 8 is a TEM photograph of the plate-shaped silicon composite of Figure 1.
  • Figure 9 is an exemplary diagram showing a mixture of graphite and a plate-shaped silicon composite of a silicon anode material for a lithium-ion secondary battery to which boron oxide is applied according to an embodiment of the present invention.
  • Figure 10 is an example diagram showing a mixture of plate-shaped silicon composite and graphite in a form different from that of Figure 9.
  • Figure 11 is a flow chart schematically showing a method of manufacturing a silicon anode material for a lithium ion secondary battery to which boron oxide is applied according to an embodiment of the present invention.
  • Figure 12 is a flow chart of Figure 11 further including a pretreatment step, a secondary disintegration step, and a mixing step.
  • Figure 13 is a graph of the half cell charge/discharge test results of Comparative Example 1.
  • Figure 14 is a graph of the half cell charge/discharge test results of Comparative Example 2.
  • Figure 15 is a graph of the half cell charge/discharge test results of Comparative Example 3.
  • Figure 16 is a graph of the half cell charge/discharge test results of Example 1.
  • Figure 17 is a graph of the half cell charge/discharge test results of Example 2.
  • the silicon anode material for a lithium-ion secondary battery to which boron oxide is applied includes a plate-shaped silicon composite made of plate-shaped silicon formed from a waste silicon kerf, wherein the plate-shaped silicon composite is made by disintegrating the plate-shaped silicon.
  • a silicon anode material for lithium ion secondary batteries can be provided.
  • Figure 1 is an exemplary diagram showing the appearance of a plate-shaped silicon composite of a silicon anode material for a lithium-ion secondary battery to which boron oxide is applied according to an embodiment of the present invention
  • Figure 2 is a diagram showing the appearance of a plate-shaped silicon composite for a lithium-ion secondary battery to which boron oxide is applied according to an embodiment of the present invention.
  • It is an SEM photo of plate-shaped silicon used in the production of a silicon anode material
  • Figure 3 is an example diagram showing the appearance of the plate-shaped silicon of Figure 2
  • Figure 4 is a silicon anode material for a lithium ion secondary battery to which boron oxide is applied according to an embodiment of the present invention.
  • Figure 5 is an exemplary diagram showing an oxide film formed on the plate-shaped silicon particle of Figure 4
  • Figures 6a and 6b are TEM images of the plate-shaped silicon particle with an oxide film formed in Figure 5
  • Figure 7 is an exemplary diagram showing a boron oxide coating film formed on the plate-shaped silicon particle with the oxide film of Figure 5
  • Figure 8 is a TEM photograph of the plate-shaped silicon composite of Figure 1
  • Figure 9 is an oxidation according to an embodiment of the present invention.
  • FIG. 10 is an example diagram showing a mixture of plate-shaped silicon composite and graphite of a silicon anode material for a lithium-ion secondary battery to which boron is applied
  • Figure 10 is an example diagram showing a mixture of plate-shaped silicon composite and graphite in a form different from Figure 9.
  • the present invention relates to a silicon anode material that not only has a low unit cost by using plate-shaped silicon formed from a waste silicon kerf, but also has improved initial capacity and life performance by applying boron oxide.
  • the silicon anode material for a lithium ion secondary battery to which boron oxide is applied may include a plate-shaped silicon composite (1).
  • the plate-shaped silicon composite 1 is made of plate-shaped silicon formed from a waste silicon kerf, and includes plate-shaped silicon particles 10a, an oxide film 11, a boron oxide coating film 12, and a carbon coating film 13. can do.
  • the plate-shaped silicon 10 used here may be a powder formed in the form of a plate, as shown in FIGS. 2 and 3, and is a waste silicon cuff generated in the process of thinly slicing a silicon ingot for solar cells or semiconductors. It can be formed as (cutting differential).
  • a waste silicon cuff can be obtained through classification, washing, precipitation, and drying steps. It is preferable to use a waste silicone cuff made through a diamond wire saw in order to obtain a waste silicone cuff with high thickness uniformity, but is not limited to this.
  • a diamond wire saw is a method of cutting silicon ingots using water or diethylene glycol as a lubricant with diamond particles randomly embedded on the surface of a carbon steel wire called a piano wire of about 50 ⁇ m.
  • Silicon ingots include single crystal ingots and polycrystalline ingots, and have the advantage that all cutting fines are suitable for the plate-shaped silicon (10) of the present invention.
  • the plate-shaped silicon 10 formed of a waste silicon kerf may be formed to have an average thickness of 10 to 100 nm and an average length of 10 ⁇ m or less.
  • the average thickness of the plate-shaped silicon 10 is less than 10 nm, too much is lost when forming the oxide film 11, and the initial capacity may be less than 60% of the pre-processing value, which may greatly reduce economic efficiency. If the average thickness exceeds 100 mm, This is because, in the case where the ratio of the oxide film 11 is less than 20%, the number of particles increases and the effect of improving life performance may be greatly reduced.
  • the average length of the plate-shaped silicon (10) is more than 10 ⁇ m
  • the average length of the plate-shaped silicon (10) is more than 10 ⁇ m
  • a lot of empty space is formed between the particles of the graphite (2) and the plate-shaped silicon composite (1), thereby increasing the porosity in the same space.
  • the discharge capacity may drop significantly in the same volume.
  • the plate-shaped silicon 10 may be bent and curled as strong force is applied during the cutting process and the silicon separates from the single crystal into a plate shape, resulting in many fine single crystals being weakly attached. Accordingly, the plate-shaped silicon 10 can be used by making it more suitable for an anode material through crushing pretreatment. That is, it is preferable to crush the plate-shaped silicon 10 and use it as plate-shaped silicon particles 10a.
  • the plate-shaped silicon 10 can be crushed and pre-treated to form plate-shaped silicon particles 10a as shown in FIG. 4, and can be pre-treated by wet milling and drying.
  • the method of wet milling the plate-shaped silicon 10 may be a bead mill (ball mill), ultrasonic dispersion, or high-pressure homogenizer dispersion method.
  • the bead mill method is a method in which plate-shaped silicon (10) is mixed in a range of 5 to 30% in water or an organic solvent, then rotated with zirconia or alumina beads in a zirconia or alumina container and crushed by friction and impact force between balls.
  • the bead mill preferably uses beads with a diameter of 0.5 to 3 mm, and crushes them by rotating them at 1,000 to 5,000 rpm based on a container diameter of 100 mm.
  • the impact force may be weak and crushing may not be possible, and if it is more than 3mm, the number of beads may be too small, reducing the probability of collision with the plate-shaped silicon (10), making crushing time unnecessary. It can be long.
  • the rotation speed is less than 1000 rpm, the energy required for crushing may be low and the energy required for crushing may not be sufficient, and if it exceeds 5000 rpm, bead wear may occur due to excessive high energy and may be mixed with the plate-shaped silicon 10 as an impurity.
  • the ultrasonic dispersion method attaches an amplifying horn and a vibrating horn to an ultrasonic vibrator and applies ultrasonic vibration to the solution to disperse or destroy the particles in the solution. It is desirable for ultrasonic dispersion to process the plate-shaped silicon 10 under the conditions of a frequency of 20 to 35 KHz, an amplitude of 20 to 200 ⁇ m, and a vibrator power consumption of 200 W or more.
  • ultrasonic dispersion is possible by mixing plate-shaped silicon 10 in water or an organic solvent in a range of 30% or less and then receiving ultrasonic vibrations from a plurality of oscillators while passing through a passage in which a plurality of oscillators are arranged in a row.
  • the vibrator power consumption is less than 200W, the energy may be too low and almost no shredding may occur.
  • the frequency is less than 20 KHz, it may not be easy to operate because it cannot exceed the audible frequency, and if it is more than 35 KHz, it only reduces the durability of the vibrator and vibration generator and has no effect on shredding or improving the working environment.
  • the plate-shaped silicon 10 is mixed in water or an organic solvent in an amount exceeding 30%, the viscosity may become too high and the transmission range of ultrasonic vibration may not be wide.
  • a high-pressure homogenizer is a device that disperses or destroys the powder in the solution by applying pressure using a pump to pass the solution through a fine nozzle in the opposite direction.
  • a high-pressure homogenizer that combine collision, such as a method of colliding with a diamond plate after passing through a fine nozzle, or a method of colliding solutions with each other by passing through a nozzle in both directions.
  • plate-shaped silicon (10) is mixed in a range of 30% or less in water or an organic solvent using a high-pressure homogenizer dispersion method, then pressurized at 500 bar or more, passed through a fine nozzle of 50 to 200 ⁇ m, and collided or mutually dispersed on the diamond plate. It is better to use the collision method.
  • the plate-shaped silicon 10 is mixed in water or an organic solvent in an amount exceeding 30%, the viscosity may become too high, making it difficult to inject into the fine nozzle. Additionally, if the pressure is less than 500 bar, the collision energy may be weakened and crushing may be almost impossible.
  • the fine nozzle diameter is less than 50 ⁇ m, nozzle clogging may occur frequently, which may make process operation difficult. If it exceeds 200 ⁇ m, the collision energy may be so weak that crushing may hardly occur.
  • crushed plate-shaped silicon particles 10a obtained from one of the bead mill, disperser, and homogenizer are recovered in a dried powder state.
  • various drying devices capable of vaporizing moisture and organic solvents can be used, but it is preferable to use a spray dryer or a disk dryer.
  • the spray dryer spreads the dispersion solution containing the crushed plate-shaped silicon particles (10a) into the atmosphere through a spray nozzle or a rotating disk nozzle (atomizer) and injects heated gas to rotate around the nozzle, causing the solution to scatter.
  • the disk dryer has high thermal efficiency, and the dispersion solution containing the crushed plate-shaped silicon particles (10a) is dropped little by little onto a diagonally inclined heated rotating disk, dried, and the dried residue, the crushed and dried plate-shaped silicon particles (10a), is dried. It is recovered by scraping it with a knife. Disk dryers have good thermal efficiency, but have the disadvantage of recovering powder with a high apparent density.
  • the plate-shaped silicon particles (10a) crushed and dried through the above pretreatment process have the moisture and lubricant in the waste silicon cuff removed, but for easy reaction with gas in the post-process, the plate-shaped silicon particles (10a) can be broken down to form spaces between particles.
  • the crushed and dried plate-shaped silicon particles (10a) have an apparent density of 1 to 2 g/cm3, and by grinding at 3,000 rpm under air, plate-shaped silicon particles (10a) having an apparent density of 0.2 to 0.4 g/cm3 are obtained. can do.
  • the average distance between particles of the crushed plate-shaped silicon particles 10a may be 3 to 10 times greater than that of the crushed and dried plate-shaped silicon particles 10a.
  • the oxide film 11 can be formed more uniformly.
  • the oxide film 11 may be formed by oxidizing the surface of the plate-shaped silicon particle 10a.
  • This oxide film 11 ensures a high charge/discharge speed because the plate-shaped silicon 10 has a high specific surface area of 10 m2/g or more and has a large contact area with the electrolyte or electrolyte. However, due to rapid charge/discharge, silicon fracture occurs quickly. It was formed to solve the problem, and can slow down the charging and discharging speed.
  • the oxide film 11 is formed by further oxidizing the natural oxide film naturally formed on the surface of the plate-shaped silicon particle 10a, and can be said to be formed thicker than the natural oxide film.
  • the oxide film 11 is formed in an amorphous state, and when lithium approaches the oxide film 11, the gap between the oxide films 11 is filled with lithium and an electrically conductive line penetrating the oxide film 11 may be formed. Accordingly, the oxide film 11 can allow the electrolyte solution or lithium in the electrolyte to slowly diffuse into the plate-shaped silicon particles 10a.
  • the charging capacity is somewhat lower than that of existing silicon, but the charging and discharging life can be dramatically increased.
  • the oxide film 11 may have an average thickness of 2 to 10 nm. If the average thickness of the oxide film 11 is less than 2 nm, a non-uniform oxide film 11 in the form of a point may be formed on the surface of the plate-shaped silicon particle 10a, and the unoxidized portion on the surface of the plate-shaped silicon particle 10a may be in the form of a point. Since a large number of oxides are generated between the oxide films 11, the effect provided by the uniform oxide film 11 cannot be achieved. In other words, the lifespan performance improvement effect may not be desirable.
  • the irreversible capacity which is the main reason for the decrease in initial discharge capacity, increases significantly to more than 30%, which may increase lithium consumption.
  • the boron oxide coating film 12 may be formed by coating boron oxide on the surface of the plate-shaped silicon particle 10a on which the oxide film 11 is formed. This boron oxide coating film 12 may be formed to improve the disadvantage of increasing initial irreversibility due to the oxide film 11 combining with lithium during initial charging and failing to release lithium during discharging.
  • Boron oxide has the characteristic of being crystalline at a relatively low temperature, so crystalline properties can be added to the amorphous oxide film 11, and through this, the bond between the oxide film 11 and lithium can be reduced without consuming lithium. Boron oxide also has the advantage of being an inexpensive material that does not react with lithium.
  • the boron oxide coating film 12 reduces the amount of bonding with lithium of the oxide film 11 to prevent initial irreversibility from increasing and improve initial capacity and lifespan performance.
  • This boron oxide coating film 12 may not be coated on the entire surface of the plate-shaped silicon particle 10a on which the oxide film 11 is formed, but may be formed partially. This is because the boron oxide coating film 12 is formed by coating boric acid and thermal decomposition. Therefore, a non-uniform coating film may be formed.
  • the carbon coating film 13 may be formed by coating the outer surface of the plate-shaped silicon particle 10a with conductive carbon to surround the oxide film 11 and the boron oxide coating film 12.
  • This carbon coating film 13 is formed to provide electrical conductivity and smooth electron flow to the oxide film 11, which is an insulating layer.
  • the carbon coating film 13 plays a role in maintaining the amount and formation relationship of SEI (solid electrolyte interface), which is the interface between graphite and electrolyte (or electrolyte) in existing lithium ion secondary batteries, and maintains the formation relationship due to changes in material. This can eliminate the inconvenience of having to change the electrolyte (or electrolyte).
  • the carbon coating film 13 is supplied by selecting one of hydrocarbon gas, liquefied natural gas, and liquefied petroleum gas to the plate-shaped silicon particles 10a on which the oxide film 11 and the boron oxide coating film 12 are formed using a rotary kiln or kiln. It can be formed by thermal decomposition at 750 to 1000°C. The manufacturing method will be described in more detail below.
  • the carbon coating film 13 may have an average crystallinity of less than 10 graphite layers and an average thickness of 3 to 20 nm.
  • the average thickness of the carbon coating film 13 is less than 3 nm, the carbon coating film 13 is formed unevenly in the form of dots on the surface, resulting in many uncoated areas, so the lifespan improvement effect may not be significant, and if it exceeds 20 nm, the lifespan improvement effect may not be significant. In this case, excessive coating increases the number of pores inside the carbon coating film 13, so lithium fills the pores and does not escape again, which can greatly increase the irreversible capacity.
  • the silicon anode material for lithium ion secondary batteries to which boron oxide is applied may further include graphite (2).
  • the graphite 2 is a plate-shaped material, and even if it is spherical, an empty space is formed.
  • plate-shaped silicon composite (1) fills the empty space of graphite (2), thereby binding lithium. It is possible to prevent the overall expansion of the electrode due to expansion and maintain electrical connection with the electrode due to contraction. That is, the plate-shaped silicon composite (1) is bonded to the empty space of the graphite (2), thereby preventing separation from the electrode when expanded by lithium. At this time, the empty space of the graphite 2 serves as a buffer space.
  • plate-shaped silicon composite (1) and graphite (2) of the silicon anode material for lithium-ion secondary batteries to which boron oxide is applied there are two ways to mix the plate-shaped silicon composite (1) and graphite (2) of the silicon anode material for lithium-ion secondary batteries to which boron oxide is applied. 1) In the process of spheroidizing graphite (2), plate-shaped silicon composite (1) and graphite (2) are mixed. There may be a method of adding the silicon composite (1) and 2) a method of mixing the graphite (2) that has completed the spheroidization or spheroidization process and the plate-shaped silicon composite (1).
  • a silicon anode material for a lithium ion secondary battery to which boron oxide is applied by mixing graphite (2) that has completed the spheroidization or spheronization process and plate-shaped silicon composite (1), as shown in FIG. 10
  • a silicon anode material for a lithium ion secondary battery can be formed by applying simple boron oxide in the form of a plate-shaped silicon composite (1) disposed between graphite (2).
  • the plate-shaped silicon composite 1 and the graphite 2 may be mixed at a weight ratio of 1 to 10:90 to 99, and more preferably at a weight ratio of 5:95.
  • the content of the plate-shaped silicon composite (1) is lower than 1% by weight, the effect of increasing the charging capacity of the silicon anode material due to the mixing of the graphite (2) falls within the charging capacity deviation, making it difficult to determine the effect, and if it exceeds 10% by weight, the silicon particles As the number becomes greater than the number of graphite (2) particles, the uniform dispersion effect between silicon particles and graphite (2) may be reduced.
  • a method of manufacturing a silicon anode material for a lithium ion secondary battery to which boron oxide is applied according to an embodiment of the present invention as described above will be described below.
  • Figure 11 is a flow chart schematically showing a method of manufacturing a silicon anode material for a lithium ion secondary battery to which boron oxide is applied according to an embodiment of the present invention
  • Figure 12 is a pretreatment step, a secondary disintegration step, and a mixing step are further included in Figure 11. This is a flow chart.
  • the method for manufacturing a silicon anode material for a lithium-ion secondary battery to which boron oxide is applied includes a first disintegration step (S10), an oxidation step (S20), a boron oxide coating step (S30), and a carbon It may include a coating step (S40).
  • the plate-shaped silicon 10 formed of a waste silicon kerf is disintegrated to have an apparent density of 0.1 to 0.4 g/cm3.
  • the plate-shaped silicon 10 may be bent and curled as strong force is applied during the cutting process and the silicon separates from the single crystal into a plate shape, resulting in many fine single crystals being weakly attached. Therefore, it is necessary to disintegrate the plate-shaped silicon 10.
  • the method for manufacturing a silicon anode material for a lithium ion secondary battery to which boron oxide of the present invention is applied may include a pretreatment step (S5) before the first disintegration step (S10).
  • the pretreatment step (S5) can be performed by wet milling and drying the plate-shaped silicon 10 before the first disintegration step (S10), thereby forming plate-shaped silicon particles 10a, as shown in FIG. 4.
  • the plate-shaped silicon 10 was crushed and dried to remove moisture and lubricants in the waste silicon cuff.
  • the plate-shaped silicon 10 was crushed and dried in the first crushing step (S10).
  • the crushed and dried plate-shaped silicon 10 can be pulverized to form spaces between particles.
  • the crushed and dried plate-shaped silicon particles (10a) have an apparent density of 1 to 2 g/cm3, which is pulverized at 3,000 rpm under air in the first crushing step (S10), and have an apparent density of 0.1 to 0.4 g/cm3. Plate-shaped silicon particles 20 can be obtained.
  • the average distance between particles of the crushed plate-shaped silicon particles 10a may be 3 to 10 times greater than that of the crushed and dried plate-shaped silicon particles 10a. Therefore, the first disintegration step (S10) can ensure that the oxide film 11 is uniformly formed in the subsequent oxidation step (S20).
  • the oxidation step (S20) may form the oxide film 11 by oxidizing the surface of the plate-shaped silicon particles 10a.
  • the oxidation step (S20) may be performed by additionally oxidizing the naturally formed oxide film on the surface of the plate-shaped silicon particle 10a to form a thick oxide film.
  • an oxidizing agent may be added to the plate-shaped silicon particles 10a using a rotary kiln and heated to 700 to 1,100°C.
  • the heating temperature is less than 700°C, the formation rate of the oxide film 11 becomes too slow and the reaction time becomes excessively long, so the oxide film 11 may not be formed entirely or may be difficult to form to the desired thickness. If the heating temperature exceeds 1,100°C, In this case, the plate-shaped silicon particles 10a may be damaged due to excessive temperature or the process cost may be unnecessarily increased, which may result in inefficiency.
  • one or more of oxygen, water, and hydrogen peroxide can be used as the oxidizing agent, and the heating temperature can be adjusted depending on the type of oxidizing agent.
  • hydrogen peroxide when used as an oxidizing agent, it can be heated to 700 to 1,100°C, and when oxygen is used as an oxidizing agent, it can be heated to 900 to 1,100°C.
  • the rotary kiln uses a continuous heating furnace, so it has good thermal efficiency and can shorten working time.
  • the rotary kiln is composed of an input part for feeding the material to be treated into the kiln main body, a heat treatment section equipped with a kiln body for heating, and a discharge portion for discharging the heat-treated material.
  • the objects to be treated are continuously mixed and moved, so a uniform and thick oxide film 11 is formed, and the difference in the ratio of the oxide film 11 between particles can be reduced.
  • the boron oxide coating film 12 can be formed by coating boron oxide on the surface of the plate-shaped silicon particle 10a on which the oxide film 11 is formed.
  • the boron oxide coating film 12 can be formed partially rather than on the entire surface of the plate-shaped silicon particle 10a on which the oxide film 11 is formed, which is achieved by coating boric acid and thermal decomposition to produce boron oxide. Since the coating film 12 is formed, a non-uniform coating film can be formed.
  • the plate-shaped silicon particles (10a) with the oxide film (11) formed after completing the oxidation step (S20) are dispersed by adding them to an aqueous boric acid solution, then dried through a dryer such as a spray dryer or a disk dryer, and then pulverized. It can be pulverized to an apparent density of 0.1 to 0.4 g/cm3.
  • the boron oxide coating film 12 can be formed by heating to 550 to 700° C. using a rotary kiln to convert boric acid into boron oxide.
  • the heating temperature is less than 550°C, the boron oxide does not melt all and the adhesion to the oxide film 11 may decrease, and if the heating temperature exceeds 700°C, the amount melted and blown away through vaporization increases, which may reduce the coating effect.
  • the process of converting boric acid to boron oxide involves an exothermic process and agglomeration occurs between particles, so the particles are pulverized through a grinder to form a distance between them.
  • the apparent density of the particles is preferably 0.1 to 0.4 g/cm3 as described above, but is not limited thereto.
  • the surface of the plate-shaped silicon particles (10a) on which the oxide film (11) and the boron oxide coating film (12) are formed can be coated with conductive carbon to create the plate-shaped silicon composite (1) on which the carbon coating film (13) is formed.
  • the carbon coating step (S40) can provide electrical conductivity and smooth electron flow to the oxide film 11, which is an insulating layer, by forming a carbon coating film 13 on the surface of the plate-shaped silicon particles 10a.
  • one of hydrocarbon gas, liquefied natural gas, and liquefied petroleum gas can be selected and added to the plate-shaped silicon particles 10a using a rotary kiln or kiln, and thermally decomposed at 750 to 1000 ° C.
  • hydrocarbon gas is a gas composed of carbon and hydrogen bonds, C 2 H 2 (acetylline), C 2 H 6 (ethane), C 2 H 4 (ethylene), CH 4 (methane), C 3 H 8 ( Propane), C 4 H 10 (butane), C 3 H 6 (propylene), C 4 H 8 (butylene), etc.
  • Hydrocarbon gas can be produced by vaporizing and thermally decomposing a hydrocarbon solution consisting of C, H, and O, such as ethanol, methanol, and toluene.
  • the plate-shaped silicon particles (10a) on which the oxide film 11 and the boron oxide coating film 12 are formed are thermally decomposed at 750 to 800 ° C. using ethylene gas as a hydrocarbon gas, or using liquefied natural gas. It is preferable to form the carbon coating film 13 by thermally decomposing the plate-shaped silicon particles 10a on which the oxide film 11 and the boron oxide coating film 12 are formed at 950 to 1,000° C., but the method is not limited thereto.
  • the decomposition rate is less than 50%, resulting in unnecessary gas consumption, and if the temperature is higher than 800°C, the decomposition speed increases and a large amount of unnecessary by-product called carbon black can be produced.
  • the decomposition rate is less than 50%, which results in unnecessary gas consumption. If the temperature is above 1000°C, the decomposition speed increases and a large amount of unnecessary by-product called carbon black can be produced. there is.
  • the method of manufacturing a silicon anode material for a lithium ion secondary battery to which boron oxide is applied may further include a secondary disintegration step (S35) after the boron oxide coating step (S30).
  • the second disintegration step (S35) can reduce the density by disintegrating the plate-shaped silicon particles (10a) on which the oxide film 11 and the boron oxide coating film 12 are formed, which have been aggregated after the boron oxide coating step (S30).
  • the plate-shaped silicon particles 10a on which the oxide film 11 and the boron oxide coating film 12 are formed can be pulverized with air in a pin mill with a radius of 110 to 130 mm and 3300 to 3500 rpm.
  • This second disintegration step (S35) separates the plate-shaped silicon particles (10a) on which the aggregated oxide film 11 and the boron oxide coating film 12 are formed, and the particles are 0.1 to 0.4 in the same way as the first disintegration step (S10). It can be made to have an apparent density of g/cm3. Accordingly, the second disintegration step (S35) can ensure that the carbon coating film 13 is formed uniformly in the carbon coating step (S40), which is a post-process.
  • the method of manufacturing a silicon anode material for lithium ion secondary batteries to which boron oxide is applied may further include a mixing step (S50) after the carbon coating step (S40).
  • the plate-shaped silicon composite (1) and graphite (2) are mixed to form a silicon negative electrode material for a lithium-ion secondary battery to which spherical boron oxide is applied or a lithium-ion secondary battery to which simple boron oxide is applied. Silicon anode materials for batteries can be manufactured.
  • the plate-shaped silicon composite (1) may be added during the process of spheroidizing the graphite (2), or the graphite (2) that has completed the spheroidization or spheroidization process may be mixed with the plate-shaped silicon composite (1).
  • the plate-shaped silicon composite (1) when adding the plate-shaped silicon composite (1) in the process of spheroidizing the graphite (2) in the mixing step (S50), as shown in FIG. 9, the plate-shaped silicon composite (1) is formed between the plates of the graphite (2). ) is inserted, a silicon anode material for a lithium ion secondary battery to which spherical boron oxide in the form of spherical or spherical graphite (2) is applied can be manufactured.
  • the plate-shaped silicon composite (1) is formed between the graphite (2).
  • a silicon anode material for a lithium ion secondary battery using simple boron oxide in the form of an arrangement can be manufactured.
  • the graphite 2 undergoes a spheroidization or spheronization process, because spherical graphite has a low anisotropy and is advantageous for maintaining uniformity of voltage and current distribution.
  • spherical graphite has a low anisotropy and is advantageous for maintaining uniformity of voltage and current distribution.
  • flake-shaped graphite deteriorates the processability due to reduced fluidity during the subsequent mixing and slurry process with solvents or binders, and it is difficult to form a coating layer of a certain thickness, which can cause problems such as peeling. there is.
  • the spheroidization process removes the rough parts of the flake-shaped carbon material through mechanical rotation and smoothes the surface of the particle to make it spherical.
  • the unit cost of the silicon anode material for a lithium-ion secondary battery to which boron oxide is applied uses plate-shaped silicon formed from a waste silicon kerf, which can be reduced.
  • the polycrystalline silicon ingot was cooled, lubricated, and cut with a mixture of water and diethylene glycol using a 50 ⁇ m diameter diamond wioso, and 5,000 ml of a 5% mixed solution of plate-shaped silicon was recovered.
  • the dispersion solution was injected from a spray dryer into an atomizer disk rotating at 15,000 rpm at a rate of 20 ml per minute and dried at 140 degrees to obtain plate-shaped silicon particles.
  • Low-density plate-shaped silicon particles were made by grinding with air in a pin mill with a radius of 120 mm and 3400 rpm.
  • the plate-shaped silicon particles were kept in a rotary kiln at 800°C for 10 minutes, and an oxide film was formed by bubbling and injecting hydrogen peroxide with nitrogen to oxidize them.
  • the plate-shaped silicon particles with the oxide film formed were dispersed in an aqueous solution of boric acid for 30 minutes using a 3,000 rpm mixer, and then injected into an atomizer disk rotating at 15,000 rpm in a spray dryer at a rate of 20 ml per minute and dried at 140°C.
  • boric acid was decomposed while remaining in a rotary kiln at 700°C for 10 minutes, and boron oxide was partially coated to form a boron oxide coating film.
  • Plate-shaped silicon particles with an oxide film and a boron oxide coating film were kept in a rotary kiln at 800°C for 10 minutes while ethylene gas was blown at 0.1 M/min. It was added at a high rate to form a carbon coating film on the surface, creating a plate-shaped silicon composite.
  • the prepared plate-shaped silicon composite was mixed with a binder and a conductive material, applied to copper foil, and punched into a coin shape.
  • a positive electrode was used by punching lithium foil into a coin shape, a separator and electrolyte were added, and the battery was assembled into a half-cell lithium ion battery.
  • the plate-shaped silicon composite prepared in Example 1 and the spherical graphite were put into a dry ball mill at a weight ratio of 5:95 and mixed for 10 seconds to obtain a silicon anode material for a lithium ion secondary battery to which boron oxide was applied.
  • a half-cell lithium ion battery was manufactured in the same manner as Example 1 using the silicon anode material for lithium ion secondary batteries to which the boron oxide was applied.
  • the polycrystalline silicon ingot was cooled, lubricated, and cut with a mixture of water and diethylene glycol using a 50 ⁇ m diameter diamond wioso, and 5,000 ml of a 5% mixed solution of plate-shaped silicon was recovered.
  • the dispersion solution was injected from a spray dryer into an atomizer disk rotating at 15,000 rpm at a rate of 20 ml per minute and dried at 140 degrees to obtain plate-shaped silicon particles.
  • Low-density plate-shaped silicon particles were made by grinding with air in a pin mill with a radius of 120 mm and 3400 rpm. While plate-shaped silicon particles were kept in a rotary kiln at 800°C for 10 minutes, ethylene gas was blown at 0.1 M/min.
  • Carbon-coated silicon particles were manufactured by adding the product at a high rate to form a carbon coating film on the surface.
  • the prepared carbon-coated silicon particles, graphite, binder, and conductive material were mixed, applied to copper foil, and punched into a coin shape.
  • a positive electrode was used by punching lithium foil into a coin shape, a separator and electrolyte were added, and the battery was assembled into a half-cell lithium ion battery.
  • the carbon-coated silicon particles prepared in Comparative Example 2 and spheroidized graphite were added to a dry ball mill at a weight ratio of 5:95 and mixed for 10 seconds to obtain a negative electrode material.
  • the anode material was applied to copper foil and punched into a coin shape.
  • a positive electrode was used by punching lithium foil into a coin shape, a separator and electrolyte were added, and the battery was assembled into a half-cell lithium ion battery.
  • the capacity was measured at 25°C and a charge/discharge current of 0.1C, and the lifespan was measured from 20 to 300 cycles at 25°C and a charge/discharge current of 0.1C.
  • Figures 13 to 17 are graphs of half cell charge/discharge test results for Comparative Examples 1 to 3 and Examples 1 and 2, respectively.
  • Comparative Example 1 showed a low initial capacity of 358 mAh/g, but it was confirmed that the lifespan performance satisfied 300 cycles (Figure 13)
  • Example 1 the initial capacity was slightly lower compared to Comparative Example 2, but it was confirmed that the lifespan performance was significantly improved, and the initial capacity was confirmed to be significantly increased compared to Comparative Example 1 (FIG. 16).
  • Example 2 it was confirmed that both the initial capacity and lifetime performance were improved compared to Comparative Example 2 without an oxide film and a boron oxide coating film (FIG. 17).

Abstract

The present invention relates to a silicon anode material, having boron oxide applied thereto, for a lithium ion secondary battery, and may provide a silicon anode material which has boron oxide applied thereto and is for a lithium ion secondary battery, the anode material comprising a plate-shaped silicon complex produced using plate-shaped silicon formed from waste silicon kerf, wherein the plate-shaped silicon complex comprises: plate-shaped silicon particles formed by crushing plate-shaped silicon and having an apparent density of 0.1-0.4g/cm3; an oxide film formed by oxidizing the surface of the plate-shaped silicon particles; a boron oxide coating film formed by coating boron oxide on the surface of the plate-shaped silicon particles on which the oxide film has been formed; and a carbon coating film formed by coating conductive carbon on the exterior of the plate-shaped silicon particles so as to cover the oxide film and the boron oxide coating film.

Description

산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재Silicon anode material for lithium-ion secondary batteries with boron oxide applied
본 발명은 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재에 관한 것으로, 더욱 자세하게는 폐실리콘 커프(Silicon kerf)로 형성된 판상의 실리콘을 사용하여 단가가 낮을 뿐만 아니라 산화붕소를 적용하여 초기 용량과 수명 성능이 향상된 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재에 관한 것이다.The present invention relates to a silicon anode material for lithium-ion secondary batteries to which boron oxide is applied. More specifically, by using plate-shaped silicon formed from a waste silicon kerf, not only is the unit cost low, but the initial capacity and lifespan are improved by applying boron oxide. This relates to a silicon anode material for lithium-ion secondary batteries using boron oxide with improved performance.
일반적으로 리튬이온이차전지의 음극활물질은 흑연(Graphite)을 사용해왔다. 흑연은 이론용량 372mAh/g의 리튬이온 충전용량을 가지며, 실제는 360mAh/g의 용량을 나타내는 소재로 층구조를 이루는데 리튬이 층간에 삽입되어 충전되는 메커니즘을 가져왔다.Generally, graphite has been used as the negative electrode active material for lithium-ion secondary batteries. Graphite has a theoretical capacity of 372 mAh/g of lithium ion charging capacity, and in reality, it is a material with a capacity of 360 mAh/g and has a layered structure, with a mechanism in which lithium is inserted between layers and charged.
한편, 흑연보다 큰용량을 가진 음극재용 리튬이온 저장물질로 실리콘(Silicon)이 있다. 실리콘은 이론용량 4200mAh/g을 가진 물질이다. 하지만 4200mAh/g까지 충전되면서 실리콘 하나에 리튬이온 4개가 결합하게 되어 부피가 3배 이상 팽창하게 된다. 부피가 팽창된 실리콘은 리튬이 빠져나가면 원래 상태로 복귀되지 못하고 크랙이 발생하고, 미세한 나노입자로 분리되어 상당수가 전해질 또는 전해액과 전기적 연결이 끊어져서 다시 리튬을 충전할 수 없게 된다. 이런 이유로 실리콘 음극활물질은 충방전 수명이 짧아 흑연을 대체하는 음극활물질로 사용되지 못 해왔다.Meanwhile, silicon is a lithium ion storage material for anode materials that has a larger capacity than graphite. Silicon is a material with a theoretical capacity of 4200mAh/g. However, when charged to 4200 mAh/g, four lithium ions are combined with one silicon, causing the volume to expand more than three times. Silicon, which has expanded in volume, cannot return to its original state when lithium escapes, cracks occur, and is separated into fine nanoparticles, many of which are electrically disconnected from the electrolyte or electrolyte solution, making it impossible to recharge lithium. For this reason, silicon anode active material has a short charge/discharge life and has not been used as an anode active material to replace graphite.
실리콘 음극활물질의 충방전에 의한 크랙을 막거나 크랙이 발생하지 않을 더 작은 사이즈로 만들기 위한 기술적 개선이 많이 시도되었으나 성공적이지 못했다.Many technological improvements have been attempted to prevent cracks caused by charging and discharging of silicon anode active materials or to make them smaller to prevent cracks from occurring, but they have not been successful.
음극활물질로 사용하는 실리콘은 순도 99.9% 이상의 금속 실리콘을 주로 그 원료로 해왔다. 나노사이즈의 실리콘을 사용하면 리튬 충방전에 의한 크랙이 적어지는 것을 발견한 이래로 나노실리콘을 만들기 위한 노력이 많이 이루어져왔다.Silicon used as a negative electrode active material is mainly made of metallic silicon with a purity of 99.9% or higher. Since it was discovered that cracks caused by lithium charging and discharging are reduced when nano-sized silicon is used, much effort has been made to create nano-silicon.
구체적으로, 플라즈마를 써서 마이크로 입자를 분해해서 나노사이즈로 재결합시키는 방법, 실리콘을 작은 로드로 만들어 대전류를 흘려 용액 중에서 폭발적으로 기화시켜서 나노사이즈로 만드는 방법, 실란가스나 액체로 녹여서 열분해시킨 뒤, 나노사이즈로 재결합시키는 방법 등이다.Specifically, a method of using plasma to decompose micro particles and recombine them into nano size, a method of making silicon into a small rod and explosively vaporizing it in a solution by passing a large current to make it into nano size, melting it with silane gas or liquid and thermally decomposing it, and then making it into nano size. How to recombine by size, etc.
본 발명에서는 태양전지 산업 또는 반도체 산업에서 실리콘 웨이퍼를 얻기 위해 금속 실리콘 덩어리를 얇게 자르는 과정에서 발생하는 폐실리콘 커프(Silicon kerf)를 이용한다. 여기서, 폐실리콘 커프는 태양전지 산업 또는 반도체 산업에서 사용하는 99.9999999% ~ 99.999999999%의 순도를 갖고 있는 고순도 실리콘이며, 와이어 형태의 톱을 사용하므로 나노 두께를 가진 판상의 물질로 떨어져 나온다. 이와 같은 고순도의 판상 실리콘은 좋은 리튬이차전지용 음극활물질의 후보물질이 된다.In the present invention, waste silicon kerf (silicon kerf) generated in the process of cutting a lump of metal silicon into thin pieces to obtain a silicon wafer in the solar cell industry or semiconductor industry is used. Here, the waste silicon cuff is high-purity silicon with a purity of 99.9999999% to 99.999999999% used in the solar cell industry or semiconductor industry, and by using a wire-shaped saw, it comes off as a nano-thick plate-shaped material. Such high-purity plate-shaped silicon is a good candidate for anode active material for lithium secondary batteries.
종래의 기술로서 대한민국 등록특허공보 제10-1847235호 리튬이온 이차전지 음극용 흑연 재료 및 그 제조방법, 리튬이온 이차전지(2011.12.05)가 공개되어 있다.As a conventional technology, Republic of Korea Patent Publication No. 10-1847235, graphite material for negative electrode of lithium ion secondary battery and its manufacturing method, lithium ion secondary battery (December 5, 2011) is disclosed.
상기와 같은 문제를 해결하고자, 본 발명은 폐실리콘 커프(Silicon kerf)로 형성된 판상의 실리콘을 사용하여 단가가 낮을 뿐만 아니라 산화붕소를 적용하여 초기 용량과 수명 성능이 향상된 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재를 제공하는데 목적이 있다.In order to solve the above problems, the present invention uses plate-shaped silicon formed from waste silicon kerf to not only lower the unit price but also apply boron oxide to improve initial capacity and life performance by applying boron oxide lithium ion secondary. The purpose is to provide silicon anode materials for batteries.
상기와 같은 과제를 해결하기 위하여, 본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재는 폐실리콘 커프(Silicon kerf)로 형성된 판상 실리콘으로 제조된 판상 실리콘 복합체를 포함하되, 상기 판상 실리콘 복합체는, 상기 판상 실리콘을 해쇄하여 형성된 0.1 내지 0.4g/㎤의 겉보기 밀도를 가지는 판상 실리콘 입자; 상기 판상 실리콘 입자의 표면을 산화시켜 형성된 산화막; 상기 산화막이 형성된 판상 실리콘 입자의 표면에 산화붕소를 코팅하여 형성된 산화붕소 코팅막 및 상기 판상 실리콘 입자 외각에 상기 산화막과 산화붕소 코팅막을 감싸도록 전도성 카본으로 코팅되어 형성된 카본 코팅막을 포함하는 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재를 제공할 수 있다.In order to solve the above problems, the silicon anode material for a lithium-ion secondary battery to which boron oxide is applied according to an embodiment of the present invention includes a plate-shaped silicon composite made of plate-shaped silicon formed from a waste silicon kerf, wherein the plate-shaped The silicon composite includes plate-shaped silicon particles having an apparent density of 0.1 to 0.4 g/cm3 formed by pulverizing the plate-shaped silicon; An oxide film formed by oxidizing the surface of the plate-shaped silicon particles; Boron oxide is applied, including a boron oxide coating film formed by coating boron oxide on the surface of the plate-shaped silicon particle on which the oxide film is formed, and a carbon coating film formed by coating the outer shell of the plate-shaped silicon particle with conductive carbon to surround the oxide film and the boron oxide coating film. A silicon anode material for lithium ion secondary batteries can be provided.
또한 상기 판상 실리콘 입자는, 판상 실리콘을 습식밀링하고 건조되어 얻어진 것을 특징으로 한다.In addition, the plate-shaped silicon particles are characterized in that they are obtained by wet milling and drying plate-shaped silicon.
또한 상기 판상 실리콘은, 평균 두께가 10 내지 100㎚, 평균 길이가 10㎛ 이하인 것을 특징으로 한다.In addition, the plate-shaped silicon is characterized by an average thickness of 10 to 100 nm and an average length of 10 μm or less.
또한 상기 산화막은, 평균 두께가 2 내지 10㎚인 것을 특징으로 한다.Additionally, the oxide film is characterized by an average thickness of 2 to 10 nm.
또한 상기 산화막은, 상기 판상 실리콘 입자에 산화제를 투입하고 700 내지 1,100℃로 가열하여 형성된 것을 특징으로 한다.In addition, the oxide film is formed by adding an oxidizing agent to the plate-shaped silicon particles and heating them to 700 to 1,100°C.
또한 상기 산화붕소 코팅막은, 상기 산화막이 형성된 판상 실리콘 입자에 붕산 수용액을 투입하고 550 내지 700℃로 가열하여 형성된 것을 특징으로 한다.In addition, the boron oxide coating film is characterized in that it is formed by adding an aqueous boric acid solution to the plate-shaped silicon particles on which the oxide film is formed and heating it to 550 to 700 ° C.
또한 상기 카본 코팅막은, 평균 두께가 3 내지 20㎚인 것을 특징으로 한다.Additionally, the carbon coating film is characterized by an average thickness of 3 to 20 nm.
또한 상기 카본 코팅막은, 상기 산화막과 산화붕소 코팅막이 형성된 판상 실리콘 입자에 탄화수소가스, 액화천연가스 및 액화석유가스 중 하나를 선택하여 투입하고, 750 내지 1000℃에서 열분해시켜 형성된 것을 특징으로 한다.In addition, the carbon coating film is characterized in that it is formed by selectively adding one of hydrocarbon gas, liquefied natural gas, and liquefied petroleum gas to the plate-shaped silicon particles on which the oxide film and boron oxide coating film are formed, and thermally decomposing it at 750 to 1000 ° C.
또한 흑연을 더 포함할 수 있다.It may also contain more graphite.
상기와 같은 본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재는 폐실리콘 커프(Silicon kerf)로 형성된 판상의 실리콘을 사용하여 단가가 저감될 수 있다.The unit cost of the silicon anode material for a lithium-ion secondary battery to which boron oxide is applied according to the embodiment of the present invention as described above can be reduced by using plate-shaped silicon formed from a waste silicon kerf.
또한, 판상의 흑연과 복합화되어 충진율이 우수할 수 있다.In addition, it can be complexed with plate-shaped graphite and have an excellent filling rate.
또한, 성능이 향상되어 동일 부피 대비 더 많은 리튬을 충전할 수 있다.Additionally, performance has improved, allowing more lithium to be charged compared to the same volume.
또한, 산화붕소를 적용하여 초기 용량과 수명 성능이 향상된 실리콘 음극재를 제조할 수 있다.In addition, by applying boron oxide, a silicon anode material with improved initial capacity and lifespan performance can be manufactured.
또한, 위에서 언급된 본 발명의 실시 예에 따른 효과는 기재된 내용에만 한정되지 않고, 명세서 및 도면으로부터 예측 가능한 모든 효과를 더 포함할 수 있다.In addition, the effects according to the embodiments of the present invention mentioned above are not limited to the contents described, and may further include all effects predictable from the specification and drawings.
도 1은 본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재의 판상 실리콘 복합체의 모습을 나타낸 예시도.Figure 1 is an exemplary diagram showing the appearance of a plate-shaped silicon composite of a silicon anode material for a lithium ion secondary battery to which boron oxide is applied according to an embodiment of the present invention.
도 2는 본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재의 제조에 사용되는 판상 실리콘의 SEM 사진.Figure 2 is an SEM photograph of plate-shaped silicon used in the production of a silicon anode material for a lithium-ion secondary battery to which boron oxide is applied according to an embodiment of the present invention.
도 3은 도 2의 판상 실리콘 모습을 나타낸 예시도.Figure 3 is an example diagram showing the appearance of the plate-shaped silicon of Figure 2.
도 4는 본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재의 판상 실리콘 입자의 모습을 나타낸 예시도.Figure 4 is an exemplary diagram showing the appearance of plate-shaped silicon particles of a silicon anode material for a lithium ion secondary battery to which boron oxide is applied according to an embodiment of the present invention.
도 5는 도 4의 판상 실리콘 입자에 산화막이 형성된 모습을 나타낸 예시도.Figure 5 is an example diagram showing an oxide film formed on the plate-shaped silicon particle of Figure 4.
도 6a 및 6b는 도 5의 산화막이 형성된 판상 실리콘 입자의 TEM 사진.FIGS. 6A and 6B are TEM photographs of the plate-shaped silicon particles on which the oxide film of FIG. 5 is formed.
도 7은 도 5의 산화막이 형성된 판상 실리콘 입자에 산화붕소 코팅막이 형성된 모습을 나타낸 예시도.Figure 7 is an exemplary diagram showing a boron oxide coating film formed on the plate-shaped silicon particle on which the oxide film of Figure 5 is formed.
도 8은 도 1의 판상 실리콘 복합체의 TEM 사진.Figure 8 is a TEM photograph of the plate-shaped silicon composite of Figure 1.
도 9는 본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재의 판상 실리콘 복합체와 흑연이 혼합된 모습을 나타낸 예시도.Figure 9 is an exemplary diagram showing a mixture of graphite and a plate-shaped silicon composite of a silicon anode material for a lithium-ion secondary battery to which boron oxide is applied according to an embodiment of the present invention.
도 10은 도 9와 다른 형태로 판상 실리콘 복합체와 흑연이 혼합된 모습을 나타낸 예시도.Figure 10 is an example diagram showing a mixture of plate-shaped silicon composite and graphite in a form different from that of Figure 9.
도 11은 본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재의 제조방법을 개략적으로 나타낸 흐름도.Figure 11 is a flow chart schematically showing a method of manufacturing a silicon anode material for a lithium ion secondary battery to which boron oxide is applied according to an embodiment of the present invention.
도 12는 도 11에 전처리단계, 2차 해쇄단계 및 혼합단계가 더 포함된 흐름도.Figure 12 is a flow chart of Figure 11 further including a pretreatment step, a secondary disintegration step, and a mixing step.
도 13은 비교예 1의 Half cell 충방전 시험 결과 그래프.Figure 13 is a graph of the half cell charge/discharge test results of Comparative Example 1.
도 14는 비교예 2의 Half cell 충방전 시험 결과 그래프.Figure 14 is a graph of the half cell charge/discharge test results of Comparative Example 2.
도 15는 비교예 3의 Half cell 충방전 시험 결과 그래프.Figure 15 is a graph of the half cell charge/discharge test results of Comparative Example 3.
도 16은 실시예 1의 Half cell 충방전 시험 결과 그래프.Figure 16 is a graph of the half cell charge/discharge test results of Example 1.
도 17은 실시예 2의 Half cell 충방전 시험 결과 그래프.Figure 17 is a graph of the half cell charge/discharge test results of Example 2.
본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재는 폐실리콘 커프(Silicon kerf)로 형성된 판상 실리콘으로 제조된 판상 실리콘 복합체를 포함하되, 상기 판상 실리콘 복합체는, 상기 판상 실리콘을 해쇄하여 형성된 0.1 내지 0.4g/㎤의 겉보기 밀도를 가지는 판상 실리콘 입자; 상기 판상 실리콘 입자의 표면을 산화시켜 형성된 산화막; 상기 산화막이 형성된 판상 실리콘 입자의 표면에 산화붕소를 코팅하여 형성된 산화붕소 코팅막 및 상기 판상 실리콘 입자 외각에 상기 산화막과 산화붕소 코팅막을 감싸도록 전도성 카본으로 코팅되어 형성된 카본 코팅막을 포함하는 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재를 제공할 수 있다.The silicon anode material for a lithium-ion secondary battery to which boron oxide is applied according to an embodiment of the present invention includes a plate-shaped silicon composite made of plate-shaped silicon formed from a waste silicon kerf, wherein the plate-shaped silicon composite is made by disintegrating the plate-shaped silicon. Plate-shaped silicon particles having an apparent density of 0.1 to 0.4 g/cm3 formed by: An oxide film formed by oxidizing the surface of the plate-shaped silicon particles; Boron oxide is applied, including a boron oxide coating film formed by coating boron oxide on the surface of the plate-shaped silicon particle on which the oxide film is formed, and a carbon coating film formed by coating the outer shell of the plate-shaped silicon particle with conductive carbon to surround the oxide film and the boron oxide coating film. A silicon anode material for lithium ion secondary batteries can be provided.
이하, 도면을 참조한 본 발명의 설명은 특정한 실시 형태에 대해 한정되지 않으며, 다양한 변환을 가할 수 있고 여러 가지 실시예를 가질 수 있다. 또한, 이하에서 설명하는 내용은 본 발명의 사상 및 기술 범위에 포함되는 모든 변환, 균등물 내지 대체물을 포함하는 것으로 이해되어야 한다.Hereinafter, the description of the present invention with reference to the drawings is not limited to specific embodiments, and various changes may be made and various embodiments may be possible. In addition, the content described below should be understood to include all conversions, equivalents, and substitutes included in the spirit and technical scope of the present invention.
이하의 설명에서 제1, 제2 등의 용어는 다양한 구성요소들을 설명하는데 사용되는 용어로서, 그 자체에 의미가 한정되지 아니하며, 하나의 구성요소를 다른 구성요소로부터 구별하는 목적으로만 사용된다.In the following description, the terms first, second, etc. are terms used to describe various components, and their meaning is not limited, and is used only for the purpose of distinguishing one component from other components.
본 명세서 전체에 걸쳐 사용되는 동일한 참조번호는 동일한 구성요소를 나타낸다.Like reference numerals used throughout this specification refer to like elements.
본 발명에서 사용되는 단수의 표현은 문맥상 명백하게 다르게 뜻하지 않는 한, 복수의 표현을 포함한다. 또한, 이하에서 기재되는 "포함하다", "구비하다" 또는 "가지다" 등의 용어는 명세서상에 기재된 특징, 숫자, 단계, 동작, 구성요소, 부품 또는 이들을 조합한 것이 존재함을 지정하려는 것으로 해석되어야 하며, 하나 또는 그 이상의 다른 특징들이나, 숫자, 단계, 동작, 구성요소, 부품 또는 이들을 조합한 것들의 존재 또는 부가 가능성을 미리 배제하지 않는 것으로 이해되어야 한다.As used herein, singular expressions include plural expressions, unless the context clearly dictates otherwise. In addition, terms such as “comprise,” “provide,” or “have” used below are intended to designate the presence of features, numbers, steps, operations, components, parts, or a combination thereof described in the specification. It should be construed and understood as not excluding in advance the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts or combinations thereof.
이하, 본 발명의 실시예를 첨부한 도 1 내지 도 17을 참조하여 상세히 설명하기로 한다.Hereinafter, an embodiment of the present invention will be described in detail with reference to the accompanying FIGS. 1 to 17.
도 1은 본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재의 판상 실리콘 복합체의 모습을 나타낸 예시도이고, 도 2는 본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재의 제조에 사용되는 판상 실리콘의 SEM 사진이고, 도 3은 도 2의 판상 실리콘 모습을 나타낸 예시도이고, 도 4는 본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재의 판상 실리콘 입자의 모습을 나타낸 예시도이고, 도 5는 도 4의 판상 실리콘 입자에 산화막이 형성된 모습을 나타낸 예시도이고, 도 6a 및 6b는 도 5의 산화막이 형성된 판상 실리콘 입자의 TEM 사진이고, 도 7은 도 5의 산화막이 형성된 판상 실리콘 입자에 산화붕소 코팅막이 형성된 모습을 나타낸 예시도이고, 도 8은 도 1의 판상 실리콘 복합체의 TEM 사진이고, 도 9는 본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재의 판상 실리콘 복합체와 흑연이 혼합된 모습을 나타낸 예시도이며, 도 10은 도 9와 다른 형태로 판상 실리콘 복합체와 흑연이 혼합된 모습을 나타낸 예시도이다.Figure 1 is an exemplary diagram showing the appearance of a plate-shaped silicon composite of a silicon anode material for a lithium-ion secondary battery to which boron oxide is applied according to an embodiment of the present invention, and Figure 2 is a diagram showing the appearance of a plate-shaped silicon composite for a lithium-ion secondary battery to which boron oxide is applied according to an embodiment of the present invention. It is an SEM photo of plate-shaped silicon used in the production of a silicon anode material, Figure 3 is an example diagram showing the appearance of the plate-shaped silicon of Figure 2, and Figure 4 is a silicon anode material for a lithium ion secondary battery to which boron oxide is applied according to an embodiment of the present invention. It is an exemplary diagram showing the appearance of a plate-shaped silicon particle, Figure 5 is an exemplary diagram showing an oxide film formed on the plate-shaped silicon particle of Figure 4, Figures 6a and 6b are TEM images of the plate-shaped silicon particle with an oxide film formed in Figure 5, Figure 7 is an exemplary diagram showing a boron oxide coating film formed on the plate-shaped silicon particle with the oxide film of Figure 5, Figure 8 is a TEM photograph of the plate-shaped silicon composite of Figure 1, and Figure 9 is an oxidation according to an embodiment of the present invention. This is an example diagram showing a mixture of plate-shaped silicon composite and graphite of a silicon anode material for a lithium-ion secondary battery to which boron is applied, and Figure 10 is an example diagram showing a mixture of plate-shaped silicon composite and graphite in a form different from Figure 9.
본 발명은 폐실리콘 커프(Silicon kerf)로 형성된 판상의 실리콘을 사용하여 단가가 낮을 뿐만 아니라 산화붕소를 적용하여 초기 용량과 수명 성능이 향상된 실리콘 음극재에 관한 것이다.The present invention relates to a silicon anode material that not only has a low unit cost by using plate-shaped silicon formed from a waste silicon kerf, but also has improved initial capacity and life performance by applying boron oxide.
도 1을 참조하면, 본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재는 판상 실리콘 복합체(1)를 포함할 수 있다.Referring to FIG. 1, the silicon anode material for a lithium ion secondary battery to which boron oxide is applied according to an embodiment of the present invention may include a plate-shaped silicon composite (1).
상기 판상 실리콘 복합체(1)는 폐실리콘 커프(Silicon kerf)로 형성된 판상 실리콘으로 제조된 것으로, 판상 실리콘 입자(10a), 산화막(11), 산화붕소 코팅막(12) 및 카본 코팅막(13)을 포함할 수 있다.The plate-shaped silicon composite 1 is made of plate-shaped silicon formed from a waste silicon kerf, and includes plate-shaped silicon particles 10a, an oxide film 11, a boron oxide coating film 12, and a carbon coating film 13. can do.
여기서 사용되는 판상 실리콘(10)은 도 2 및 도 3과 같이, 판 형태로 형성된 분말일 수 있는데, 태양전지 또는 반도체용 실리콘 잉곳(Ingot)을 얇게 슬라이싱(Slicing)하는 과정에서 발생하는 폐실리콘 커프(절삭미분)로 형성될 수 있다.The plate-shaped silicon 10 used here may be a powder formed in the form of a plate, as shown in FIGS. 2 and 3, and is a waste silicon cuff generated in the process of thinly slicing a silicon ingot for solar cells or semiconductors. It can be formed as (cutting differential).
실리콘 잉곳 절삭 방법은 일반적으로 3 내지 4 종류의 방법이 있으며, 모든 방법에는 분급, 세척, 침전 및 건조 단계를 거쳐 폐실리콘 커프를 얻을 수 있다. 폐실리콘 커프는 높은 두께 균일도를 가지는 폐실리콘 커프를 얻기 위해, 다이아몬드 와이어쏘(Diamond wire saw)를 통해 만들어진 것을 사용하는 게 바람직하나, 이에 한정하지는 않는다. There are generally 3 to 4 types of silicon ingot cutting methods, and in all methods, a waste silicon cuff can be obtained through classification, washing, precipitation, and drying steps. It is preferable to use a waste silicone cuff made through a diamond wire saw in order to obtain a waste silicone cuff with high thickness uniformity, but is not limited to this.
구체적으로, 다이어몬드 와이어쏘는 50㎛ 내외의 피아노선이라는 탄소강 와이어 표면에 다이아몬드 입자가 랜덤하게 박힌 것으로 물 또는 디에틸렌글리콜 성분을 윤활제로 하여 실리콘 잉곳을 자르는 방식이다. 실리콘 잉곳에는 단결정 잉곳과 다결정 잉곳이 있으며, 모든 절삭미분이 본 발명의 판상 실리콘(10)으로 적합하다는 장점이 있다.Specifically, a diamond wire saw is a method of cutting silicon ingots using water or diethylene glycol as a lubricant with diamond particles randomly embedded on the surface of a carbon steel wire called a piano wire of about 50㎛. Silicon ingots include single crystal ingots and polycrystalline ingots, and have the advantage that all cutting fines are suitable for the plate-shaped silicon (10) of the present invention.
폐실리콘 커프(Silicon kerf)로 형성된 판상 실리콘(10)은 평균 두께가 10 내지 100㎚, 평균 길이가 10㎛ 이하로 형성될 수 있다. The plate-shaped silicon 10 formed of a waste silicon kerf may be formed to have an average thickness of 10 to 100 nm and an average length of 10 μm or less.
여기서 판상 실리콘(10)의 평균 두께가 10nm 미만일 경우 산화막(11) 형성 시 잃는 부분이 너무 많아서 초기 용량이 처리 전 대비 60%도 되지 않을 수 있어 경제성이 크게 떨어질 수 있고, 평균 두께가 100mm 초과일 경우 산화막(11)의 비율이 20%도 되지 않는 입자가 많아져 수명 성능 개선 효과가 크게 떨어질 수 있기 때문이다.Here, if the average thickness of the plate-shaped silicon 10 is less than 10 nm, too much is lost when forming the oxide film 11, and the initial capacity may be less than 60% of the pre-processing value, which may greatly reduce economic efficiency. If the average thickness exceeds 100 mm, This is because, in the case where the ratio of the oxide film 11 is less than 20%, the number of particles increases and the effect of improving life performance may be greatly reduced.
또한 판상 실리콘(10)의 평균 길이가 10㎛ 초과일 경우 흑연(2)과의 혼합 시, 흑연(2)과 판상 실리콘 복합체(1) 입자 사이에 빈 공간이 많이 형성되어 동일 공간에 기공율이 커지고 충진율이 떨어져 동일 부피에서 방전 용량이 크게 떨어질 수 있다.In addition, when the average length of the plate-shaped silicon (10) is more than 10㎛, when mixed with graphite (2), a lot of empty space is formed between the particles of the graphite (2) and the plate-shaped silicon composite (1), thereby increasing the porosity in the same space. As the charging rate decreases, the discharge capacity may drop significantly in the same volume.
판상 실리콘(10)은 절삭과정에서 강한 힘이 주어지면서 실리콘이 단결정에서 판상으로 떨어져 나오므로 휘고 말리게 되고, 많은 미세 단결정이 약하게 부착된 형태로 만들어질 수 있다. 이에, 판상 실리콘(10)은 파쇄 전처리를 통해 음극재에 더 적합한 상태로 만들어 사용될 수 있다. 즉, 판상 실리콘(10)을 파쇄하여 판상 실리콘 입자(10a)로 사용하는 것이 바람직한 것이다.The plate-shaped silicon 10 may be bent and curled as strong force is applied during the cutting process and the silicon separates from the single crystal into a plate shape, resulting in many fine single crystals being weakly attached. Accordingly, the plate-shaped silicon 10 can be used by making it more suitable for an anode material through crushing pretreatment. That is, it is preferable to crush the plate-shaped silicon 10 and use it as plate-shaped silicon particles 10a.
한편, 판상 실리콘(10)은 파쇄되어 도 4와 같은 판상 실리콘 입자(10a) 형태로 만들어지기 위해 전처리가 될 수 있는데, 습식밀링하고 건조되는 것으로 전처리 될 수 있다.Meanwhile, the plate-shaped silicon 10 can be crushed and pre-treated to form plate-shaped silicon particles 10a as shown in FIG. 4, and can be pre-treated by wet milling and drying.
이때, 판상 실리콘(10)을 습식밀링하는 방식은 비드밀(볼밀), 초음파분산, 고압균질기분산 방식이 사용될 수 있다. At this time, the method of wet milling the plate-shaped silicon 10 may be a bead mill (ball mill), ultrasonic dispersion, or high-pressure homogenizer dispersion method.
먼저, 비드밀 방식은 물 또는 유기용매에 판상 실리콘(10)을 5 ~ 30% 범위로 혼합한 후 지르코니아 또는 알루미나 용기에서 지르코니아 또는 알루미나 비드과 함께 회전하여 볼간의 마찰력과 충격력에 의해 파쇄하는 방식이다. 비드밀은 0.5 내지 3㎜직경의 비드를 사용하고, 용기의 직경 100㎜ 기준 1,000 내지 5000rpm으로 회전시켜 파쇄하는 것이 바람직하다.First, the bead mill method is a method in which plate-shaped silicon (10) is mixed in a range of 5 to 30% in water or an organic solvent, then rotated with zirconia or alumina beads in a zirconia or alumina container and crushed by friction and impact force between balls. The bead mill preferably uses beads with a diameter of 0.5 to 3 mm, and crushes them by rotating them at 1,000 to 5,000 rpm based on a container diameter of 100 mm.
비드밀 사용 시, 비드의 직경이 0.5mm 미만일 경우 충격력이 약해져 파쇄가 거의 되지 않을 수 있으며, 3mm 초과일 경우 비드의 숫자가 너무 적어져서 판상 실리콘(10)과 충돌 확률 저하로 파쇄 시간이 불필요하게 길어질 수 있다.When using a bead mill, if the bead diameter is less than 0.5mm, the impact force may be weak and crushing may not be possible, and if it is more than 3mm, the number of beads may be too small, reducing the probability of collision with the plate-shaped silicon (10), making crushing time unnecessary. It can be long.
또한 회전속도가 1000rpm 미만일 경우 저에너지로 파쇄에 필요한 에너지가 부족하여 파쇄가 거의 되지 않을 수 있고, 5000rpm 초과일 경우 과도한 고에너지로 비드 마모가 발생하고 불순물로 판상 실리콘(10)과 섞일 수 있다.In addition, if the rotation speed is less than 1000 rpm, the energy required for crushing may be low and the energy required for crushing may not be sufficient, and if it exceeds 5000 rpm, bead wear may occur due to excessive high energy and may be mixed with the plate-shaped silicon 10 as an impurity.
초음파분산 방식은 초음파 진동자에 증폭혼과 진동혼을 부착하여 용액에 초음파 진동을 가하여 용액 내 알갱이를 분산 또는 파괴하는 방식이다. 초음파분산은 주파수 20 내지 35KHz, 진폭 20 내지 200um, 진동자 전력소비량 200W 이상 조건에서 판상 실리콘(10)을 처리하는 것이 바람직하다. 또한, 초음파분산은 물 또는 유기용매에 판상 실리콘(10)을 30% 이하 범위로 혼합한 후 진동자 다수가 일렬로 배치된 유로를 통과하면서 다수 진동자의 초음파진동을 받아서 파쇄가 가능하다.The ultrasonic dispersion method attaches an amplifying horn and a vibrating horn to an ultrasonic vibrator and applies ultrasonic vibration to the solution to disperse or destroy the particles in the solution. It is desirable for ultrasonic dispersion to process the plate-shaped silicon 10 under the conditions of a frequency of 20 to 35 KHz, an amplitude of 20 to 200 μm, and a vibrator power consumption of 200 W or more. In addition, ultrasonic dispersion is possible by mixing plate-shaped silicon 10 in water or an organic solvent in a range of 30% or less and then receiving ultrasonic vibrations from a plurality of oscillators while passing through a passage in which a plurality of oscillators are arranged in a row.
이때, 진동자 전력소비량이 200W 미만일 경우 너무 낮은 에너지로 파쇄가 거의 되지 않을 수 있다. 또한 주파수가 20 KHz 미만일 경우 가청 주파수를 넘기지 못해 운영이 용이하지 않을 수 있으며, 35 KHz 초과일 경우 진동자와 진동발생기의 내구성만 떨어뜨리고 파쇄와 작업환경 개선 효과는 없다.At this time, if the vibrator power consumption is less than 200W, the energy may be too low and almost no shredding may occur. In addition, if the frequency is less than 20 KHz, it may not be easy to operate because it cannot exceed the audible frequency, and if it is more than 35 KHz, it only reduces the durability of the vibrator and vibration generator and has no effect on shredding or improving the working environment.
또한 물 또는 유기용매에 판상 실리콘(10)이 30% 초과 범위로 혼합될 경우 점도가 너무 높아져 초음파 진동의 전달 범위가 넓게 이루어지지 않을 수 있기 때문이다.In addition, if the plate-shaped silicon 10 is mixed in water or an organic solvent in an amount exceeding 30%, the viscosity may become too high and the transmission range of ultrasonic vibration may not be wide.
고압균질기는 펌프를 사용하여 압력을 가하여 용액을 반대방향의 미세노즐로 통과시켜서 용액 내 분말을 분산시키거나 파괴하는 장치이다. 고압균질기는 미세노즐 통과 후 다이아몬드판에 충돌시키는 방법, 양방향으로 노즐을 통과시켜 용액끼리 충돌시키는 방법 등 충돌을 결합하여 사용하는 방식도 있다. 본 발명에는 고압균질기분산 방식으로 물 또는 유기용매에 판상 실리콘(10)을 30% 이하 범위로 혼합한 후, 500bar 이상으로 가압하여 50 내지 200㎛의 미세 노즐을 통과시키고 다이아몬드판에 충돌 또는 상호 충돌하는 방식을 사용하는 것이 좋다.A high-pressure homogenizer is a device that disperses or destroys the powder in the solution by applying pressure using a pump to pass the solution through a fine nozzle in the opposite direction. There are also methods of using a high-pressure homogenizer that combine collision, such as a method of colliding with a diamond plate after passing through a fine nozzle, or a method of colliding solutions with each other by passing through a nozzle in both directions. In the present invention, plate-shaped silicon (10) is mixed in a range of 30% or less in water or an organic solvent using a high-pressure homogenizer dispersion method, then pressurized at 500 bar or more, passed through a fine nozzle of 50 to 200㎛, and collided or mutually dispersed on the diamond plate. It is better to use the collision method.
이때, 물 또는 유기용매에 판상 실리콘(10)이 30% 초과 범위로 혼합되면, 점도가 너무 높아져 미세 노즐에 주입이 용이하지 않을 수 있다. 또한 압력이 500bar 미만일 경우 충돌에너지가 약해져 파쇄가 거의 되지 않을 수 있다.At this time, if the plate-shaped silicon 10 is mixed in water or an organic solvent in an amount exceeding 30%, the viscosity may become too high, making it difficult to inject into the fine nozzle. Additionally, if the pressure is less than 500 bar, the collision energy may be weakened and crushing may be almost impossible.
또한 미세노즐 직경이 50㎛ 미만일 경우 노즐 막힘이 자주 발생하여 공정 운영이 어려울 수 있고, 200㎛ 초과일 경우 충돌에너지가 너무 약해져서 파쇄가 거의 되지 않을 수 있다.Additionally, if the fine nozzle diameter is less than 50㎛, nozzle clogging may occur frequently, which may make process operation difficult. If it exceeds 200㎛, the collision energy may be so weak that crushing may hardly occur.
또한, 상기의 비드밀, 분산기 및 균질기 중 하나로부터 얻어진 파쇄된 판상 실리콘 입자(10a)는 건조된 분말 상태로 회수되는 것이 바람직하다. Additionally, it is preferable that the crushed plate-shaped silicon particles 10a obtained from one of the bead mill, disperser, and homogenizer are recovered in a dried powder state.
이때, 건조를 위한 장치는 수분 및 유기용매 기화 기능이 있는 다양한 장치의 사용이 가능하나, 스프레이 드라이어, 디스크 드라이어를 사용하는 것이 바람직하다.At this time, various drying devices capable of vaporizing moisture and organic solvents can be used, but it is preferable to use a spray dryer or a disk dryer.
여기서, 스프레이 드라이어는 파쇄된 판상 실리콘 입자(10a)가 포함된 분산용액을 스프레이 노즐 또는 회전원판 노즐(Atomizer)을 통해 대기 중에 퍼트리고 뜨거워진 기체를 노즐 주변을 회전하도록 주입하여 용액이 비산된 상태에서 건조하는 장치로 낮은 겉보기 밀도를 가지는 건조 분말을 얻을 수 있는 장점이 있으나, 열효율이 좋지 않다.Here, the spray dryer spreads the dispersion solution containing the crushed plate-shaped silicon particles (10a) into the atmosphere through a spray nozzle or a rotating disk nozzle (atomizer) and injects heated gas to rotate around the nozzle, causing the solution to scatter. There is an advantage in obtaining dry powder with a low apparent density using a drying device, but the thermal efficiency is not good.
디스크 드라이어는 열효율이 높으며, 대각선으로 기울어진 가열된 회전디스크에 파쇄된 판상 실리콘 입자(10a)가 포함된 분산용액을 조금씩 떨어뜨려서 건조시키고 건조 잔류물인 파쇄 및 건조된 판상 실리콘 입자(10a)를 세라믹 나이프로 긁어서 회수하는 방식이다. 디스크 드라이어는 열 효율이 좋으나 높은 겉보기 밀도를 가지는 분말이 회수되는 단점이 있다.The disk dryer has high thermal efficiency, and the dispersion solution containing the crushed plate-shaped silicon particles (10a) is dropped little by little onto a diagonally inclined heated rotating disk, dried, and the dried residue, the crushed and dried plate-shaped silicon particles (10a), is dried. It is recovered by scraping it with a knife. Disk dryers have good thermal efficiency, but have the disadvantage of recovering powder with a high apparent density.
상기와 같은 전처리 과정을 통해 파쇄 및 건조된 판상 실리콘 입자(10a)는 폐실리콘 커프에 있던 수분과 윤활제가 제거된 상태지만, 후공정에서 기체와의 용이한 반응을 위해, 판상 실리콘 입자(10a)를 해쇄하여 입자간의 공간을 형성할 수 있다. The plate-shaped silicon particles (10a) crushed and dried through the above pretreatment process have the moisture and lubricant in the waste silicon cuff removed, but for easy reaction with gas in the post-process, the plate-shaped silicon particles (10a) can be broken down to form spaces between particles.
파쇄 및 건조된 판상 실리콘 입자(10a)는 1 내지 2g/㎤의 겉보기 밀도를 가지는데 공기 하에서 3,000rpm으로 분쇄하는 것으로, 0.2 내지 0.4g/㎤의 겉보기 밀도를 가지는 판상 실리콘 입자(10a)를 획득할 수 있다.The crushed and dried plate-shaped silicon particles (10a) have an apparent density of 1 to 2 g/cm3, and by grinding at 3,000 rpm under air, plate-shaped silicon particles (10a) having an apparent density of 0.2 to 0.4 g/cm3 are obtained. can do.
이에 해쇄된 판상 실리콘 입자(10a)는 입자간의 평균거리가 파쇄 및 건조된 판상 실리콘 입자(10a) 보다 3 내지 10배 늘어날 수 있다. Accordingly, the average distance between particles of the crushed plate-shaped silicon particles 10a may be 3 to 10 times greater than that of the crushed and dried plate-shaped silicon particles 10a.
이와 같이 판상 실리콘(10)을 그대로 사용하지 않고, 판상 실리콘 입자(10a) 형태로 만들어 사용함으로써, 산화막(11)이 보다 균일하게 형성되도록 할 수 있다.In this way, by using the plate-shaped silicon particles 10a instead of using the plate-shaped silicon 10 as is, the oxide film 11 can be formed more uniformly.
도 5, 도 6a 및 도 6b를 참조하면, 산화막(11)은 판상 실리콘 입자(10a)의 표면을 산화시켜 형성될 수 있다. Referring to FIGS. 5, 6A, and 6B, the oxide film 11 may be formed by oxidizing the surface of the plate-shaped silicon particle 10a.
이러한 산화막(11)은, 판상 실리콘(10)이 비표면적이 10㎡/g 이상으로 높아 전해액 또는 전해질과 접촉면적이 커서 높은 충방전 속도를 보장하지만, 빠른 충방전으로 인해 실리콘 파쇄가 빠르게 발생한다는 문제점을 해결하기 위해 형성된 것으로, 충방전 속도를 떨어뜨릴 수 있다.This oxide film 11 ensures a high charge/discharge speed because the plate-shaped silicon 10 has a high specific surface area of 10 m2/g or more and has a large contact area with the electrolyte or electrolyte. However, due to rapid charge/discharge, silicon fracture occurs quickly. It was formed to solve the problem, and can slow down the charging and discharging speed.
구체적으로, 산화막(11)은 판상 실리콘 입자(10a)의 표면에 자연적으로 형성되어 있는 자연 산화막을 추가로 산화시켜 형성된 것으로, 자연 산화막 보다 두껍게 형성된 것이라고 할 수 있다.Specifically, the oxide film 11 is formed by further oxidizing the natural oxide film naturally formed on the surface of the plate-shaped silicon particle 10a, and can be said to be formed thicker than the natural oxide film.
이때, 산화막(11)은 비정질 상태로 형성되고, 산화막(11)에 리튬이 접근할 경우 산화막(11) 틈새에 리튬이 충진되면서 산화막(11)을 관통하는 전기전도성 라인이 형성될 수 있다. 이에 산화막(11)은 판상 실리콘 입자(10a)에 전해액 또는 전해질의 리튬이 천천히 확산되어 들어가도록 할 수 있다.At this time, the oxide film 11 is formed in an amorphous state, and when lithium approaches the oxide film 11, the gap between the oxide films 11 is filled with lithium and an electrically conductive line penetrating the oxide film 11 may be formed. Accordingly, the oxide film 11 can allow the electrolyte solution or lithium in the electrolyte to slowly diffuse into the plate-shaped silicon particles 10a.
이와 같이 산화막(11)을 통해 리튬과 판상 실리콘 입자(10a)의 결합속도를 낮춤으로써, 충전용량은 기존 실리콘보다 다소 낮지만 충방전 수명은 극적으로 늘어나도록 할 수 있다.In this way, by lowering the bonding speed of lithium and the plate-shaped silicon particles 10a through the oxide film 11, the charging capacity is somewhat lower than that of existing silicon, but the charging and discharging life can be dramatically increased.
또한 산화막(11)은 평균 두께가 2 내지 10㎚일 수 있다. 산화막(11)의 평균 두께가 2nm 미만일 경우 판상 실리콘 입자(10a) 표면에 점 형태의 불균일한 산화막(11)이 형성될 수 있으며, 이에 판상 실리콘 입자(10a) 표면에 산화되지 않은 부분이 점 형태의 산화막(11) 사이로 다수 발생하게 되어 균일한 산화막(11)이 주는 효과를 나타낼 수 없다. 즉, 수명성능 향상 효과가 바람직하게 나타나지 않을 수 있다.Additionally, the oxide film 11 may have an average thickness of 2 to 10 nm. If the average thickness of the oxide film 11 is less than 2 nm, a non-uniform oxide film 11 in the form of a point may be formed on the surface of the plate-shaped silicon particle 10a, and the unoxidized portion on the surface of the plate-shaped silicon particle 10a may be in the form of a point. Since a large number of oxides are generated between the oxide films 11, the effect provided by the uniform oxide film 11 cannot be achieved. In other words, the lifespan performance improvement effect may not be desirable.
또한 산화막(11)이 10nm 초과일 경우 초기 방전용량 감소의 주요 이유인 비가역 용량이 30%이상으로 크게 늘어나 리튬 소모가 심해질 수 있다.Additionally, if the oxide film 11 exceeds 10 nm, the irreversible capacity, which is the main reason for the decrease in initial discharge capacity, increases significantly to more than 30%, which may increase lithium consumption.
도 7을 참조하면, 산화붕소 코팅막(12)은 산화막(11)이 형성된 판상 실리콘 입자(10a)의 표면에 산화붕소가 코팅되어 형성될 수 있다. 이러한 산화붕소 코팅막(12)은 산화막(11)이 초기 충전 때 리튬과 결합하고 방전 때 리튬을 내놓지 못하여 초기 비가역이 늘어나는 단점을 개선하기 위해 형성될 수 있다.Referring to FIG. 7, the boron oxide coating film 12 may be formed by coating boron oxide on the surface of the plate-shaped silicon particle 10a on which the oxide film 11 is formed. This boron oxide coating film 12 may be formed to improve the disadvantage of increasing initial irreversibility due to the oxide film 11 combining with lithium during initial charging and failing to release lithium during discharging.
산화붕소는 비교적 낮은 온도에서 결정질을 가지는 특성이 있어, 비결정질인 산화막(11)에 결정질을 부가할 수 있으며, 이를 통해 리튬을 소비하지 않으면서 산화막(11)과 리튬의 결합을 줄일 수 있다. 산화붕소는 리튬과 반응하지 않고 저렴한 물질이라는 장점도 있다.Boron oxide has the characteristic of being crystalline at a relatively low temperature, so crystalline properties can be added to the amorphous oxide film 11, and through this, the bond between the oxide film 11 and lithium can be reduced without consuming lithium. Boron oxide also has the advantage of being an inexpensive material that does not react with lithium.
즉, 산화붕소 코팅막(12)은 산화막(11)의 리튬과의 결합량을 감소시켜 초기 비가역이 늘어나지 않도록 하고, 초기 용량과 수명 성능이 향상되도록 한다.That is, the boron oxide coating film 12 reduces the amount of bonding with lithium of the oxide film 11 to prevent initial irreversibility from increasing and improve initial capacity and lifespan performance.
이러한 산화붕소 코팅막(12)은 산화막(11)이 형성된 판상 실리콘 입자(10a) 표면 전체에 코팅되는 것이 아니라 부분적으로 형성될 수 있는데, 이는 붕산을 코팅하고 열분해하여 산화붕소 코팅막(12)이 형성되기 때문에 불균일한 코팅막이 형성될 수 있는 것이다.This boron oxide coating film 12 may not be coated on the entire surface of the plate-shaped silicon particle 10a on which the oxide film 11 is formed, but may be formed partially. This is because the boron oxide coating film 12 is formed by coating boric acid and thermal decomposition. Therefore, a non-uniform coating film may be formed.
도 1 및 도 8을 참조하면, 카본 코팅막(13)은 판상 실리콘 입자(10a) 외각에 산화막(11)과 산화붕소 코팅막(12)을 감싸도록 전도성 카본으로 코팅되어 형성될 수 있다.Referring to Figures 1 and 8, the carbon coating film 13 may be formed by coating the outer surface of the plate-shaped silicon particle 10a with conductive carbon to surround the oxide film 11 and the boron oxide coating film 12.
이러한 카본 코팅막(13)은 절연층인 산화막(11)에 전기전도성 및 원활한 전자흐름을 부여하기 위해 형성된 것이다. 즉, 카본 코팅막(13)은 기존의 리튬이온이차전지에서 흑연과 전해액(또는 전해질) 계면인 SEI(Solid electrolyte interface, 고체 전해질 계면)의 형성량과 형성관계를 유지시키는 역할을 하며, 소재 변화로 인해 전해액(또는 전해질)을 변경해야 하는 불편함을 없애 줄 수 있다.This carbon coating film 13 is formed to provide electrical conductivity and smooth electron flow to the oxide film 11, which is an insulating layer. In other words, the carbon coating film 13 plays a role in maintaining the amount and formation relationship of SEI (solid electrolyte interface), which is the interface between graphite and electrolyte (or electrolyte) in existing lithium ion secondary batteries, and maintains the formation relationship due to changes in material. This can eliminate the inconvenience of having to change the electrolyte (or electrolyte).
카본 코팅막(13)은 로타리킬른 또는 킬른을 사용하여 산화막(11)과 산화붕소 코팅막(12)이 형성된 판상 실리콘 입자(10a)에 탄화수소가스, 액화천연가스 및 액화석유가스 중 하나를 선택하여 공급하고 750 내지 1000℃에서 열분해 시키는 것으로 형성될 수 있다. 제조방법에 대해서는 하기에서 보다 자세하게 설명하기로 한다.The carbon coating film 13 is supplied by selecting one of hydrocarbon gas, liquefied natural gas, and liquefied petroleum gas to the plate-shaped silicon particles 10a on which the oxide film 11 and the boron oxide coating film 12 are formed using a rotary kiln or kiln. It can be formed by thermal decomposition at 750 to 1000°C. The manufacturing method will be described in more detail below.
또한 카본 코팅막(13)은 평균 흑연층 10층 이내의 결정성을 가지며, 평균 두께가 3 내지 20㎚일 수 있다.Additionally, the carbon coating film 13 may have an average crystallinity of less than 10 graphite layers and an average thickness of 3 to 20 nm.
이때, 카본 코팅막(13)의 평균 두께가 3nm 미만일 경우 표면에 카본 코팅막(13)이 점 형태로 불균일하게 형성되어, 코팅이 안된 부분이 다수 발생하여 수명 향상 효과가 크지 않을 수 있으며, 20nm 초과일 경우 과도한 코팅으로 카본 코팅막(13) 내부에 공극이 많아져서 리튬이 공극을 채우고 다시 빠져나가지 않아 비가역 용량이 크게 늘어날 수 있기 때문이다.At this time, if the average thickness of the carbon coating film 13 is less than 3 nm, the carbon coating film 13 is formed unevenly in the form of dots on the surface, resulting in many uncoated areas, so the lifespan improvement effect may not be significant, and if it exceeds 20 nm, the lifespan improvement effect may not be significant. In this case, excessive coating increases the number of pores inside the carbon coating film 13, so lithium fills the pores and does not escape again, which can greatly increase the irreversible capacity.
또한 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재는 흑연(2)을 더 포함할 수 있다.In addition, the silicon anode material for lithium ion secondary batteries to which boron oxide is applied may further include graphite (2).
여기서 흑연(2)은 판상 소재로, 구형화되어도 빈 공간이 형성되어 있다.Here, the graphite 2 is a plate-shaped material, and even if it is spherical, an empty space is formed.
이에 흑연(2)과 판상 실리콘 복합체(1)를 혼합하여 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재를 구성함에 따라, 흑연(2)의 빈 공간에 판상 실리콘 복합체(1)가 채워지면서 리튬 결합 시 팽창으로 인한 전극 전체 팽창을 방지하고 수축으로 인한 전극과의 전기적 연결을 유지하도록 할 수 있다. 즉, 흑연(2)의 빈 공간에 판상 실리콘 복합체(1)가 결합되는 형태로 리튬에 의해 팽창 시 전극과 분리되는 것을 방지할 수 있다. 이때, 흑연(2)의 빈 공간은 완충 공간 역할을 하게 된다.Accordingly, as graphite (2) and plate-shaped silicon composite (1) are mixed to form a silicon anode material for lithium-ion secondary batteries to which boron oxide is applied, plate-shaped silicon composite (1) fills the empty space of graphite (2), thereby binding lithium. It is possible to prevent the overall expansion of the electrode due to expansion and maintain electrical connection with the electrode due to contraction. That is, the plate-shaped silicon composite (1) is bonded to the empty space of the graphite (2), thereby preventing separation from the electrode when expanded by lithium. At this time, the empty space of the graphite 2 serves as a buffer space.
여기서 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재의 판상 실리콘 복합체(1)와 흑연(2)을 혼합하는 방법으로는, 2가지 방법이 있을 수 있는데, 1) 흑연(2)을 구상화하는 과정에서 판상 실리콘 복합체(1)를 투입하는 방법과 2) 구상화 또는 구형화 과정을 마친 흑연(2)과 판상 실리콘 복합체(1)를 혼합하는 방법이 있을 수 있다.Here, there are two ways to mix the plate-shaped silicon composite (1) and graphite (2) of the silicon anode material for lithium-ion secondary batteries to which boron oxide is applied. 1) In the process of spheroidizing graphite (2), plate-shaped silicon composite (1) and graphite (2) are mixed. There may be a method of adding the silicon composite (1) and 2) a method of mixing the graphite (2) that has completed the spheroidization or spheroidization process and the plate-shaped silicon composite (1).
1) 흑연(2)을 구상화하는 과정에서 판상 실리콘 복합체(1)를 투입하는 방법으로 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재를 제조할 경우에는, 도 9에 도시한 바와 같이, 흑연(2)의 판 사이에 판상 실리콘 복합체(1)가 삽입되면서 구상화 또는 구형화된 흑연(2) 형태의 구형화 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재가 형성될 수 있다.1) When manufacturing a silicon anode material for a lithium ion secondary battery to which boron oxide is applied by adding the plate-shaped silicon composite (1) in the process of spheroidizing the graphite (2), as shown in FIG. 9, the graphite (2) ), the plate-shaped silicon composite (1) is inserted between the plates, and a silicon anode material for a lithium ion secondary battery to which spherical boron oxide in the form of spherical or spherical graphite (2) is applied can be formed.
반면, 2) 구상화 또는 구형화 과정을 마친 흑연(2)과 판상 실리콘 복합체(1)를 혼합하는 방법으로 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재를 제조할 경우에는, 도 10에 도시한 바와 같이, 흑연(2) 사이에 판상 실리콘 복합체(1)가 배치된 형태의 단순 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재가 형성될 수 있다.On the other hand, 2) when manufacturing a silicon anode material for a lithium ion secondary battery to which boron oxide is applied by mixing graphite (2) that has completed the spheroidization or spheronization process and plate-shaped silicon composite (1), as shown in FIG. 10 Likewise, a silicon anode material for a lithium ion secondary battery can be formed by applying simple boron oxide in the form of a plate-shaped silicon composite (1) disposed between graphite (2).
이때, 판상 실리콘 복합체(1)와 흑연(2)은 1 내지 10 : 90 내지 99의 중량비로 혼합될 수 있고, 보다 바람직하게는 5 : 95의 중량비로 혼합될 수 있다.At this time, the plate-shaped silicon composite 1 and the graphite 2 may be mixed at a weight ratio of 1 to 10:90 to 99, and more preferably at a weight ratio of 5:95.
이때, 판상 실리콘 복합체(1)의 함량이 1중량% 보다 낮을 경우 흑연(2) 혼합에 따른 실리콘 음극재의 충전용량 증가 효과가 충전용량 편차 이내에 속하여 효과를 알기 어려우며, 10중량% 초과일 경우 실리콘 입자 수가 흑연(2) 입자 수보다 크게 많아져서 실리콘 입자와 흑연(2) 간 균일 분산 효과가 떨어질 수 있다.At this time, if the content of the plate-shaped silicon composite (1) is lower than 1% by weight, the effect of increasing the charging capacity of the silicon anode material due to the mixing of the graphite (2) falls within the charging capacity deviation, making it difficult to determine the effect, and if it exceeds 10% by weight, the silicon particles As the number becomes greater than the number of graphite (2) particles, the uniform dispersion effect between silicon particles and graphite (2) may be reduced.
상기와 같은 본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재를 제조하는 방법에 대하여 하기에서 설명하기로 한다.A method of manufacturing a silicon anode material for a lithium ion secondary battery to which boron oxide is applied according to an embodiment of the present invention as described above will be described below.
도 11은 본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재의 제조방법을 개략적으로 나타낸 흐름도이고, 도 12는 도 11에 전처리단계, 2차 해쇄단계 및 혼합단계가 더 포함된 흐름도이다.Figure 11 is a flow chart schematically showing a method of manufacturing a silicon anode material for a lithium ion secondary battery to which boron oxide is applied according to an embodiment of the present invention, and Figure 12 is a pretreatment step, a secondary disintegration step, and a mixing step are further included in Figure 11. This is a flow chart.
도 11을 참조하면, 본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재의 제조방법은 1차 해쇄단계(S10), 산화단계(S20), 산화붕소코팅단계(S30) 및 카본코팅단계(S40)를 포함할 수 있다. Referring to FIG. 11, the method for manufacturing a silicon anode material for a lithium-ion secondary battery to which boron oxide is applied according to an embodiment of the present invention includes a first disintegration step (S10), an oxidation step (S20), a boron oxide coating step (S30), and a carbon It may include a coating step (S40).
1차 해쇄단계(S10)는 폐실리콘 커프(Silicon kerf)로 형성된 판상 실리콘(10)을 해쇄하여 0.1 내지 0.4g/㎤의 겉보기 밀도를 가지도록 할 수 있다.In the first disintegration step (S10), the plate-shaped silicon 10 formed of a waste silicon kerf is disintegrated to have an apparent density of 0.1 to 0.4 g/cm3.
판상 실리콘(10)은 절삭과정에서 강한 힘이 주어지면서 실리콘이 단결정에서 판상으로 떨어져 나오므로 휘고 말리게 되고, 많은 미세 단결정이 약하게 부착된 형태로 만들어질 수 있다. 이에, 판상 실리콘(10)을 해쇄하는 것이 필요한 것이다.The plate-shaped silicon 10 may be bent and curled as strong force is applied during the cutting process and the silicon separates from the single crystal into a plate shape, resulting in many fine single crystals being weakly attached. Therefore, it is necessary to disintegrate the plate-shaped silicon 10.
한편, 도 12를 참조하면, 본 발명의 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재 제조방법은 1차 해쇄단계(S10) 이전에 전처리단계(S5)를 포함할 수 있다. Meanwhile, referring to FIG. 12, the method for manufacturing a silicon anode material for a lithium ion secondary battery to which boron oxide of the present invention is applied may include a pretreatment step (S5) before the first disintegration step (S10).
전처리단계(S5)는 1차 해쇄단계(S10) 이전에 판상 실리콘(10)을 습식밀링하고 건조하여, 도 4와 같은, 판상 실리콘 입자(10a)로 만들 수 있다.The pretreatment step (S5) can be performed by wet milling and drying the plate-shaped silicon 10 before the first disintegration step (S10), thereby forming plate-shaped silicon particles 10a, as shown in FIG. 4.
이러한 전처리단계(S5)를 통해 판상 실리콘(10)을 파쇄하고 건조시켜 폐실리콘 커프에 있던 수분과 윤활제가 제거되었지만, 후공정에서 기체와의 용이한 반응을 위해, 1차 해쇄단계(S10)에서 파쇄 및 건조된 판상 실리콘(10)을 해쇄하여 입자간의 공간을 형성할 수 있는 것이다. Through this pretreatment step (S5), the plate-shaped silicon 10 was crushed and dried to remove moisture and lubricants in the waste silicon cuff. However, for easy reaction with gas in the post-process, the plate-shaped silicon 10 was crushed and dried in the first crushing step (S10). The crushed and dried plate-shaped silicon 10 can be pulverized to form spaces between particles.
파쇄 및 건조된 판상 실리콘 입자(10a)은 1 내지 2g/㎤의 겉보기 밀도를 가지는데 1차 해쇄단계(S10)에서 공기 하에서 3,000rpm으로 분쇄하는 것으로, 0.1 내지 0.4g/㎤의 겉보기 밀도를 가지는 판상 실리콘 입자(20)를 획득할 수 있다.The crushed and dried plate-shaped silicon particles (10a) have an apparent density of 1 to 2 g/cm3, which is pulverized at 3,000 rpm under air in the first crushing step (S10), and have an apparent density of 0.1 to 0.4 g/cm3. Plate-shaped silicon particles 20 can be obtained.
이에 해쇄된 판상 실리콘 입자(10a)는 입자간의 평균거리가 파쇄 및 건조된 판상 실리콘 입자(10a)보다 3 내지 10배 늘어날 수 있다. 따라서 1차 해쇄단계(S10)는 후공정인 산화단계(S20)에서 산화막(11)이 균일하게 형성되도록 할 수 있다.Accordingly, the average distance between particles of the crushed plate-shaped silicon particles 10a may be 3 to 10 times greater than that of the crushed and dried plate-shaped silicon particles 10a. Therefore, the first disintegration step (S10) can ensure that the oxide film 11 is uniformly formed in the subsequent oxidation step (S20).
산화단계(S20)는 판상 실리콘 입자(10a)의 표면을 산화시켜 산화막(11)을 형성시킬 수 있다. The oxidation step (S20) may form the oxide film 11 by oxidizing the surface of the plate-shaped silicon particles 10a.
산화단계(S20)는 판상 실리콘 입자(10a)의 표면의 자연적으로 형성되어 있는 자연 산화막에 추가로 산화시켜 산화막을 두껍게 형성되도록 할 수 있다.The oxidation step (S20) may be performed by additionally oxidizing the naturally formed oxide film on the surface of the plate-shaped silicon particle 10a to form a thick oxide film.
산화단계(S20)는 로타리킬른(Rotary kiln) 을 사용하여 판상 실리콘 입자(10a)에 산화제를 투입하고 700 내지 1,100℃로 가열할 수 있다. In the oxidation step (S20), an oxidizing agent may be added to the plate-shaped silicon particles 10a using a rotary kiln and heated to 700 to 1,100°C.
이때, 가열온도가 700℃미만일 경우, 산화막(11)의 형성 속도가 너무 느려져서 반응시간이 과도하게 길어짐에 따라 산화막(11)이 전체적으로 형성되지 않거나 원하는 두께로 형성하기 어려울 수 있고, 1,100℃초과일 경우, 과도한 온도로 판상 실리콘 입자(10a)가 손상되거나 공정비용이 불필요하게 증대될 수 있어 비효율적일 수 있다. At this time, if the heating temperature is less than 700°C, the formation rate of the oxide film 11 becomes too slow and the reaction time becomes excessively long, so the oxide film 11 may not be formed entirely or may be difficult to form to the desired thickness. If the heating temperature exceeds 1,100°C, In this case, the plate-shaped silicon particles 10a may be damaged due to excessive temperature or the process cost may be unnecessarily increased, which may result in inefficiency.
여기서, 산화제는 산소, 물, 과산화수소 중 하나이상을 사용할 수 있고, 산화제의 종류에 따라 가열 온도를 조절할 수 있다. Here, one or more of oxygen, water, and hydrogen peroxide can be used as the oxidizing agent, and the heating temperature can be adjusted depending on the type of oxidizing agent.
구체적으로, 산화제로 과산화수소를 사용할 경우, 700 내지 1,100℃로 가열할 수 있고, 산화제로 산소를 사용할 경우, 900 내지 1,100℃로 가열할 수 있다. Specifically, when hydrogen peroxide is used as an oxidizing agent, it can be heated to 700 to 1,100°C, and when oxygen is used as an oxidizing agent, it can be heated to 900 to 1,100°C.
여기서, 로타리킬른은 연속식 가열로를 사용하므로 열효율이 좋고 작업시간을 단축할 수 있다. 로타리킬른은 피처리물을 킬른 본체에 투입하기 위한 투입부, 가열하기 위한 킬른 본체를 구비하는 열처리부, 가열처리된 피처리물을 배출하는 배출부로 구성되어 있다. 로타리킬른은 피처리물이 계속 혼합하면서 이동하므로 균일하고 두께가 두꺼운 산화막(11)이 형성되며 입자 간의 산화막(11) 비율의 차이를 줄일 수 있다.Here, the rotary kiln uses a continuous heating furnace, so it has good thermal efficiency and can shorten working time. The rotary kiln is composed of an input part for feeding the material to be treated into the kiln main body, a heat treatment section equipped with a kiln body for heating, and a discharge portion for discharging the heat-treated material. In the rotary kiln, the objects to be treated are continuously mixed and moved, so a uniform and thick oxide film 11 is formed, and the difference in the ratio of the oxide film 11 between particles can be reduced.
산화붕소코팅단계(S30)는 산화막(11)이 형성된 판상 실리콘 입자(10a)의 표면에 산화붕소를 코팅하여 산화붕소 코팅막(12)을 형성할 수 있다.In the boron oxide coating step (S30), the boron oxide coating film 12 can be formed by coating boron oxide on the surface of the plate-shaped silicon particle 10a on which the oxide film 11 is formed.
산화붕소코팅단계(S30)는 산화붕소 코팅막(12)을 산화막(11)이 형성된 판상 실리콘 입자(10a) 표면 전체에 코팅시키는 것이 아니라 부분적으로 형성시킬 수 있는데, 이는 붕산을 코팅하고 열분해하여 산화붕소 코팅막(12)을 형성하므로 불균일한 코팅막이 형성될 수 있는 것이다.In the boron oxide coating step (S30), the boron oxide coating film 12 can be formed partially rather than on the entire surface of the plate-shaped silicon particle 10a on which the oxide film 11 is formed, which is achieved by coating boric acid and thermal decomposition to produce boron oxide. Since the coating film 12 is formed, a non-uniform coating film can be formed.
산화붕소코팅단계(S30)는 산화단계(S20)를 마친 산화막(11)이 형성된 판상 실리콘 입자(10a)를 붕산 수용액에 투입하여 분산시킨 뒤, 스프레이 드라이어, 디스크 드라이어 등의 건조기를 통해 건조시키고 분쇄기를 이용하여 0.1 내지 0.4g/㎤의 겉보기 밀도로 분쇄할 수 있다. 그 다음, 로타리킬른을 사용하여 550 내지 700℃로 가열하여, 붕산을 산화붕소로 변환시켜 산화붕소 코팅막(12)을 형성시킬 수 있다.In the boron oxide coating step (S30), the plate-shaped silicon particles (10a) with the oxide film (11) formed after completing the oxidation step (S20) are dispersed by adding them to an aqueous boric acid solution, then dried through a dryer such as a spray dryer or a disk dryer, and then pulverized. It can be pulverized to an apparent density of 0.1 to 0.4 g/cm3. Next, the boron oxide coating film 12 can be formed by heating to 550 to 700° C. using a rotary kiln to convert boric acid into boron oxide.
이때, 가열온도가 550℃미만일 경우 산화붕소가 모두 녹지 않아서 산화막(11)에 부착력이 저하될 수 있고, 700℃초과일 경우 녹아서 기화로 날아가는 양이 많아져 코팅 효과가 저하될 수 있다.At this time, if the heating temperature is less than 550°C, the boron oxide does not melt all and the adhesion to the oxide film 11 may decrease, and if the heating temperature exceeds 700°C, the amount melted and blown away through vaporization increases, which may reduce the coating effect.
한편, 산화붕소코팅단계(S30)는 붕산이 산화붕소로 변환되는 과정에서 발열과정이 수반되어 입자간의 응집이 발생하므로, 분쇄기를 통해 입자간의 거리가 형성되도록 해쇄하는 것이다. 이때, 입자의 겉보기 밀도는 상기에서 기재한 바와 같이 0.1 내지 0.4g/㎤가 바람직하나, 이에 한정하지는 않는다.Meanwhile, in the boron oxide coating step (S30), the process of converting boric acid to boron oxide involves an exothermic process and agglomeration occurs between particles, so the particles are pulverized through a grinder to form a distance between them. At this time, the apparent density of the particles is preferably 0.1 to 0.4 g/cm3 as described above, but is not limited thereto.
카본코팅단계(S40)는 산화막(11)과 산화붕소 코팅막(12)이 형성된 판상 실리콘 입자(10a)의 표면을 전도성 카본으로 코팅하여 카본 코팅막(13)이 형성된 판상 실리콘 복합체(1)를 만들 수 있다. 카본코팅단계(S40)는 판상 실리콘 입자(10a)의 표면에 카본 코팅막(13)을 형성함으로써, 절연층인 산화막(11)에 전기전도성 및 원활한 전자흐름을 부여할 수 있다.In the carbon coating step (S40), the surface of the plate-shaped silicon particles (10a) on which the oxide film (11) and the boron oxide coating film (12) are formed can be coated with conductive carbon to create the plate-shaped silicon composite (1) on which the carbon coating film (13) is formed. there is. The carbon coating step (S40) can provide electrical conductivity and smooth electron flow to the oxide film 11, which is an insulating layer, by forming a carbon coating film 13 on the surface of the plate-shaped silicon particles 10a.
카본코팅단계(S40)는 로타리킬른 또는 킬른을 사용하여 판상 실리콘 입자(10a)에 탄화수소가스, 액화천연가스 및 액화석유가스 중 하나를 선택하여 투입하고, 750 내지 1000℃에서 열분해 시킬 수 있다. In the carbon coating step (S40), one of hydrocarbon gas, liquefied natural gas, and liquefied petroleum gas can be selected and added to the plate-shaped silicon particles 10a using a rotary kiln or kiln, and thermally decomposed at 750 to 1000 ° C.
여기서, 탄화수소가스는 카본과 수소 결합으로 이루어진 가스로, C2H2(아세틸린), C2H6(에탄), C2H4(에틸렌), CH4(메탄), C3H8(프로판), C4H10(부탄), C3H6(프로필렌), C4H8(부틸렌) 등이 사용될 수 있다. 탄화수소가스는 에탄올, 메탄올, 톨루엔 등과 같은 C, H, O로 이루어진 탄화수소 용액을 기화 및 열분해시켜 제조한 것을 사용할 수 있다. Here, hydrocarbon gas is a gas composed of carbon and hydrogen bonds, C 2 H 2 (acetylline), C 2 H 6 (ethane), C 2 H 4 (ethylene), CH 4 (methane), C 3 H 8 ( Propane), C 4 H 10 (butane), C 3 H 6 (propylene), C 4 H 8 (butylene), etc. may be used. Hydrocarbon gas can be produced by vaporizing and thermally decomposing a hydrocarbon solution consisting of C, H, and O, such as ethanol, methanol, and toluene.
카본코팅단계(S40)는 탄화수소가스로 에틸렌가스를 사용하여 산화막(11)과 산화붕소 코팅막(12)이 형성된 판상 실리콘 입자(10a)를 750 내지 800℃에서 열분해시키거나, 액화천연가스를 사용하여 산화막(11)과 산화붕소 코팅막(12)이 형성된 판상 실리콘 입자(10a)를 950 내지 1,000℃에서 열분해시켜 카본 코팅막(13)을 형성하는 것이 바람직하나, 이에 한정하지는 않는다.In the carbon coating step (S40), the plate-shaped silicon particles (10a) on which the oxide film 11 and the boron oxide coating film 12 are formed are thermally decomposed at 750 to 800 ° C. using ethylene gas as a hydrocarbon gas, or using liquefied natural gas. It is preferable to form the carbon coating film 13 by thermally decomposing the plate-shaped silicon particles 10a on which the oxide film 11 and the boron oxide coating film 12 are formed at 950 to 1,000° C., but the method is not limited thereto.
에틸렌가스를 사용할 시, 온도가 750℃미만일 경우 분해율이 50%도 되지 않아 불필요하게 가스를 소모시키게 되며, 800℃초과일 경우 분해 속도가 빨라져 카본 블랙이라는 불필요한 부산물을 다량으로 만들어 낼 수 있다.When using ethylene gas, if the temperature is less than 750℃, the decomposition rate is less than 50%, resulting in unnecessary gas consumption, and if the temperature is higher than 800℃, the decomposition speed increases and a large amount of unnecessary by-product called carbon black can be produced.
액화천연가스를 사용하는 경우 또한, 온도가 950℃미만일 경우 분해율이 50%도 되지 않아 불필요하게 가스를 소모시키게 되며, 1000℃초과일 경우 분해 속도가 빨라져 카본 블랙이라는 불필요한 부산물을 다량으로 만들어 낼 수 있다.When using liquefied natural gas, if the temperature is below 950℃, the decomposition rate is less than 50%, which results in unnecessary gas consumption. If the temperature is above 1000℃, the decomposition speed increases and a large amount of unnecessary by-product called carbon black can be produced. there is.
도 12를 참조하면, 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재의 제조방법은 산화붕소코팅단계(S30) 이후에 2차 해쇄단계(S35)를 더 포함할 수 있다.Referring to FIG. 12, the method of manufacturing a silicon anode material for a lithium ion secondary battery to which boron oxide is applied may further include a secondary disintegration step (S35) after the boron oxide coating step (S30).
2차 해쇄단계(S35)는 산화붕소코팅단계(S30) 이후에 응집되어 있는 산화막(11)과 산화붕소 코팅막(12)이 형성된 판상 실리콘 입자(10a)를 해쇄하여 저밀도화 시킬 수 있다. 2차 해쇄단계(S35)는 산화막(11)과 산화붕소 코팅막(12)이 이 형성된 판상 실리콘 입자(10a)를 반경 110 내지 130㎜, 3300 내지 3500rpm 핀밀에서 공기와 함께 분쇄할 수 있다. The second disintegration step (S35) can reduce the density by disintegrating the plate-shaped silicon particles (10a) on which the oxide film 11 and the boron oxide coating film 12 are formed, which have been aggregated after the boron oxide coating step (S30). In the second crushing step (S35), the plate-shaped silicon particles 10a on which the oxide film 11 and the boron oxide coating film 12 are formed can be pulverized with air in a pin mill with a radius of 110 to 130 mm and 3300 to 3500 rpm.
이러한 2차 해쇄단계(S35)는 응집된 산화막(11)과 산화붕소 코팅막(12)이 형성된 판상 실리콘 입자(10a)를 분리시키는 것으로, 1차 해쇄단계(S10)와 동일하게 입자가 0.1 내지 0.4g/㎤의 겉보기 밀도를 가지도록 할 수 있다. 이에, 2차 해쇄단계(S35)는 후공정인 카본코팅단계(S40)에서 카본 코팅막(13)이 균일하게 형성되도록 할 수 있다.This second disintegration step (S35) separates the plate-shaped silicon particles (10a) on which the aggregated oxide film 11 and the boron oxide coating film 12 are formed, and the particles are 0.1 to 0.4 in the same way as the first disintegration step (S10). It can be made to have an apparent density of g/cm3. Accordingly, the second disintegration step (S35) can ensure that the carbon coating film 13 is formed uniformly in the carbon coating step (S40), which is a post-process.
또한, 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재의 제조방법은 카본코팅단계(S40) 이후에, 혼합단계(S50)를 더 포함할 수 있다. In addition, the method of manufacturing a silicon anode material for lithium ion secondary batteries to which boron oxide is applied may further include a mixing step (S50) after the carbon coating step (S40).
혼합단계(S50)는 카본코팅단계(S40) 이후에 판상 실리콘 복합체(1)와 흑연(2)을 혼합하여 구형화 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재 또는 단순 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재를 제조할 수 있다.In the mixing step (S50), after the carbon coating step (S40), the plate-shaped silicon composite (1) and graphite (2) are mixed to form a silicon negative electrode material for a lithium-ion secondary battery to which spherical boron oxide is applied or a lithium-ion secondary battery to which simple boron oxide is applied. Silicon anode materials for batteries can be manufactured.
혼합단계(S50)는 흑연(2)을 구상화하는 과정에서 판상 실리콘 복합체(1)를 투입하거나, 구상화 또는 구형화 과정을 마친 흑연(2)과 판상 실리콘 복합체(1)를 혼합할 수 있다.In the mixing step (S50), the plate-shaped silicon composite (1) may be added during the process of spheroidizing the graphite (2), or the graphite (2) that has completed the spheroidization or spheroidization process may be mixed with the plate-shaped silicon composite (1).
구체적으로, 혼합단계(S50)에서 흑연(2)을 구상화하는 과정에서 판상 실리콘 복합체(1)를 투입할 경우, 도 9에 도시한 바와 같이, 흑연(2)의 판 사이에 판상 실리콘 복합체(1)가 삽입되면서 구상화 또는 구형화된 흑연(2) 형태의 구형화 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재가 제조될 수 있다. Specifically, when adding the plate-shaped silicon composite (1) in the process of spheroidizing the graphite (2) in the mixing step (S50), as shown in FIG. 9, the plate-shaped silicon composite (1) is formed between the plates of the graphite (2). ) is inserted, a silicon anode material for a lithium ion secondary battery to which spherical boron oxide in the form of spherical or spherical graphite (2) is applied can be manufactured.
반면, 혼합단계(S50)에서 구상화 또는 구형화 과정을 마친 흑연(2)과 판상 실리콘 복합체(1)를 혼합할 경우, 도 10에 도시한 바와 같이, 흑연(2) 사이에 판상 실리콘 복합체(1)가 배치된 형태의 단순 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재가 제조될 수 있다. On the other hand, when mixing the graphite (2) and the plate-shaped silicon composite (1) that have completed the spheroidization or spheroidization process in the mixing step (S50), as shown in FIG. 10, the plate-shaped silicon composite (1) is formed between the graphite (2). ) A silicon anode material for a lithium ion secondary battery using simple boron oxide in the form of an arrangement can be manufactured.
이때, 흑연(2)은 구상화 또는 구형화과정을 거치는데, 이는 구형 흑연이 이방도가 낮아 전압 및 전류 분포의 균일성 유지에 유리하기 때문이다. 반면, 플레이크상의 흑연은 재료 자체의 비등방성으로 인해, 이후 용매나 바인더와 혼합 및 슬러리화하는 과정에서 유동성 저하로 공정성이 나빠지고, 소정 두께의 도포층 형성이 어려워 박리 현상 등의 문제점이 발생할 수 있다. 일반적으로, 구상화 공정은 기계적 회전운동에 의해 플레이크상 탄소재의 거친 부분들을 제거하고 입자 표면을 매끄럽게 가공하여 구형화할 수 있다.At this time, the graphite 2 undergoes a spheroidization or spheronization process, because spherical graphite has a low anisotropy and is advantageous for maintaining uniformity of voltage and current distribution. On the other hand, due to the anisotropy of the material itself, flake-shaped graphite deteriorates the processability due to reduced fluidity during the subsequent mixing and slurry process with solvents or binders, and it is difficult to form a coating layer of a certain thickness, which can cause problems such as peeling. there is. In general, the spheroidization process removes the rough parts of the flake-shaped carbon material through mechanical rotation and smoothes the surface of the particle to make it spherical.
상기에서 설명한 바와 같이, 본 발명의 실시예에 따른 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재는 폐실리콘 커프(Silicon kerf)로 형성된 판상의 실리콘을 사용하여 단가가 저감될 수 있다.As described above, the unit cost of the silicon anode material for a lithium-ion secondary battery to which boron oxide is applied according to an embodiment of the present invention uses plate-shaped silicon formed from a waste silicon kerf, which can be reduced.
또한, 판상의 흑연과 복합화되어 충진율이 우수할 수 있다.In addition, it can be complexed with plate-shaped graphite and have an excellent filling rate.
또한, 성능이 향상되어 동일 부피 대비 더 많은 리튬을 충전할 수 있다.Additionally, performance has improved, allowing more lithium to be charged compared to the same volume.
이하에서, 실시예를 들어 본 발명에 대하여 더욱 상세하게 설명할 것이나, 이들은 단지 본 발명의 바람직한 구현예를 예시하기 위한 것으로, 실시예가 본 발명의 범위를 제한하는 것은 아니다.Hereinafter, the present invention will be described in more detail through examples, but these are merely for illustrating preferred embodiments of the present invention, and the examples do not limit the scope of the present invention.
[실시예][Example]
[실시예 1][Example 1]
다결정 실리콘 잉곳을 직경 50㎛ 다이아몬드 와이오쏘로 물과 디에틸렌글리콜 혼합액으로 냉각, 윤활 및 절단과정을 거쳐 판상 실리콘 5% 혼합용액 5,000ml을 회수하였다. 분산용액을 스프레이 드라이어에서 15,000rpm으로 회전하는 아토마이저 원판에 분당 20ml 속도로 주입하여 140도에서 건조하여 판상 실리콘 입자를 얻었다. 반경 120㎜, 3400rpm 핀밀에서 공기와 함께 분쇄하여 저밀도의 판상 실리콘 입자를 만들었다. 상기 판상 실리콘 입자를 로타리킬른 800℃에서 10분간 체류시키면서, 질소로 과산화수소를 버블링하고 주입하여 산화시키는 것으로 산화막을 형성하였다. 산화막이 형성된 판상 실리콘 입자를 붕산 수용액에 3,000rpm 믹서를 사용하여 30분간 분산시킨 뒤, 스프레이 드라이어에서 15,000rpm으로 회전하는 아토마이저 원판에 분당 20ml 속도로 주입하여 140℃에서 건조하였다. 그 다음, 로타리킬른 700℃에서 10분간 체류시키면서 붕산을 분해시켜 부분적으로 산화붕소가 코팅되어 산화붕소 코팅막이 형성되도록 하였다. 산화막과 산화붕소 코팅막이 형성된 판상 실리콘 입자를 로타리킬른 800℃에서 10분간 체류시키면서 에틸렌 가스를 0.1M/min. 속도로 투입하여 표면에 카본 코팅막이 형성되도록 하여, 판상 실리콘 복합체를 만들었다.The polycrystalline silicon ingot was cooled, lubricated, and cut with a mixture of water and diethylene glycol using a 50㎛ diameter diamond wioso, and 5,000 ml of a 5% mixed solution of plate-shaped silicon was recovered. The dispersion solution was injected from a spray dryer into an atomizer disk rotating at 15,000 rpm at a rate of 20 ml per minute and dried at 140 degrees to obtain plate-shaped silicon particles. Low-density plate-shaped silicon particles were made by grinding with air in a pin mill with a radius of 120 mm and 3400 rpm. The plate-shaped silicon particles were kept in a rotary kiln at 800°C for 10 minutes, and an oxide film was formed by bubbling and injecting hydrogen peroxide with nitrogen to oxidize them. The plate-shaped silicon particles with the oxide film formed were dispersed in an aqueous solution of boric acid for 30 minutes using a 3,000 rpm mixer, and then injected into an atomizer disk rotating at 15,000 rpm in a spray dryer at a rate of 20 ml per minute and dried at 140°C. Next, boric acid was decomposed while remaining in a rotary kiln at 700°C for 10 minutes, and boron oxide was partially coated to form a boron oxide coating film. Plate-shaped silicon particles with an oxide film and a boron oxide coating film were kept in a rotary kiln at 800°C for 10 minutes while ethylene gas was blown at 0.1 M/min. It was added at a high rate to form a carbon coating film on the surface, creating a plate-shaped silicon composite.
제조된 판상 실리콘 복합체를 바인더, 도전재와 혼합하여 구리 호일에 도포하고 코인모양으로 타공하였다. 전지셀을 만들기 위해, 양극은 리튬호일을 코인모양으로 타공하여 사용하였고, 세퍼레이터와 전해액을 넣고 리튬이온전지 Half-cell로 조립하였다.The prepared plate-shaped silicon composite was mixed with a binder and a conductive material, applied to copper foil, and punched into a coin shape. To make a battery cell, a positive electrode was used by punching lithium foil into a coin shape, a separator and electrolyte were added, and the battery was assembled into a half-cell lithium ion battery.
[실시예 2] [Example 2]
실시예 1에서 제조된 판상 실리콘 복합체와 구형화된 흑연을 5:95 무게비로 건식 볼밀에 투입하여 10초간 혼합하여 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재를 얻었다. The plate-shaped silicon composite prepared in Example 1 and the spherical graphite were put into a dry ball mill at a weight ratio of 5:95 and mixed for 10 seconds to obtain a silicon anode material for a lithium ion secondary battery to which boron oxide was applied.
상기 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재를 사용하여 실시예 1과 동일하게 리튬이온전지 Half-cell로 제조하였다.A half-cell lithium ion battery was manufactured in the same manner as Example 1 using the silicon anode material for lithium ion secondary batteries to which the boron oxide was applied.
[비교예 1][Comparative Example 1]
흑연, 바인더, 도전재와 혼합하여 구리 호일에 도포하고 코인모양으로 타공하였다. 전지셀을 만들기 위해, 양극은 리튬호일을 코인모양으로 타공하여 사용하였고, 세퍼레이터와 전해액을 넣고 리튬이온전지 Half-cell로 조립하였다.It was mixed with graphite, binder, and conductive material, applied to copper foil, and punched into a coin shape. To make a battery cell, a positive electrode was used by punching lithium foil into a coin shape, a separator and electrolyte were added, and the battery was assembled into a half-cell lithium ion battery.
[비교예 2][Comparative Example 2]
다결정 실리콘 잉곳을 직경 50㎛ 다이아몬드 와이오쏘로 물과 디에틸렌글리콜 혼합액으로 냉각, 윤활 및 절단과정을 거쳐 판상 실리콘 5% 혼합용액 5,000ml을 회수하였다. 분산용액을 스프레이 드라이어에서 15,000rpm으로 회전하는 아토마이저 원판에 분당 20ml 속도로 주입하여 140도에서 건조하여 판상 실리콘 입자를 얻었다. 반경 120㎜, 3400rpm 핀밀에서 공기와 함께 분쇄하여 저밀도의 판상 실리콘 입자를 만들었다. 판상 실리콘 입자를 로타리킬른 800℃에서 10분간 체류시키면서 에틸렌 가스를 0.1M/min. 속도로 투입하여 표면에 카본 코팅막이 형성되도록 하여 카본코팅 실리콘 입자를 제조하였다The polycrystalline silicon ingot was cooled, lubricated, and cut with a mixture of water and diethylene glycol using a 50㎛ diameter diamond wioso, and 5,000 ml of a 5% mixed solution of plate-shaped silicon was recovered. The dispersion solution was injected from a spray dryer into an atomizer disk rotating at 15,000 rpm at a rate of 20 ml per minute and dried at 140 degrees to obtain plate-shaped silicon particles. Low-density plate-shaped silicon particles were made by grinding with air in a pin mill with a radius of 120 mm and 3400 rpm. While plate-shaped silicon particles were kept in a rotary kiln at 800°C for 10 minutes, ethylene gas was blown at 0.1 M/min. Carbon-coated silicon particles were manufactured by adding the product at a high rate to form a carbon coating film on the surface.
제조된 카본코팅 실리콘 입자, 흑연, 바인더, 도전재와 혼합하여 구리 호일에 도포하고 코인모양으로 타공하였다. 전지셀을 만들기 위해, 양극은 리튬호일을 코인모양으로 타공하여 사용하였고, 세퍼레이터와 전해액을 넣고 리튬이온전지 Half-cell로 조립하였다.The prepared carbon-coated silicon particles, graphite, binder, and conductive material were mixed, applied to copper foil, and punched into a coin shape. To make a battery cell, a positive electrode was used by punching lithium foil into a coin shape, a separator and electrolyte were added, and the battery was assembled into a half-cell lithium ion battery.
[비교예 3][Comparative Example 3]
비교예 2에서 제조된 카본코팅 실리콘 입자와 구형화된 흑연을 5:95 무게비로 건식 볼밀에 투입하여 10초간 혼합하여 음극재를 얻었다.The carbon-coated silicon particles prepared in Comparative Example 2 and spheroidized graphite were added to a dry ball mill at a weight ratio of 5:95 and mixed for 10 seconds to obtain a negative electrode material.
상기 음극재를 구리 호일에 도포하고 코인모양으로 타공하였다. 전지셀을 만들기 위해, 양극은 리튬호일을 코인모양으로 타공하여 사용하였고, 세퍼레이터와 전해액을 넣고 리튬이온전지 Half-cell로 조립하였다.The anode material was applied to copper foil and punched into a coin shape. To make a battery cell, a positive electrode was used by punching lithium foil into a coin shape, a separator and electrolyte were added, and the battery was assembled into a half-cell lithium ion battery.
[실험예 1] 충방전 성능 평가[Experimental Example 1] Charging and discharging performance evaluation
실시예 1 및 2, 비교예 1 내지 3에서 제조한 Half-cell의 충방전 성능을 평가하기 위해, 용량 및 수명을 측정하였다. To evaluate the charge/discharge performance of the half-cells manufactured in Examples 1 and 2 and Comparative Examples 1 to 3, capacity and lifespan were measured.
이때, 용량은 25℃에서 충방전전류량 0.1C 조건하에서 측정하였고, 수명은 25℃에서 충방전전류량 0.1C 조건하에서 20 내지 300사이클까지 측정하였다. At this time, the capacity was measured at 25°C and a charge/discharge current of 0.1C, and the lifespan was measured from 20 to 300 cycles at 25°C and a charge/discharge current of 0.1C.
그 결과는 도 13 내지 도 17에 나타내었다. 도 12 내지 도 17은 각각 비교예 1 내지 3, 실시예 1 및 2의 Half cell 충방전 시험 결과 그래프이다.The results are shown in Figures 13 to 17. Figures 12 to 17 are graphs of half cell charge/discharge test results for Comparative Examples 1 to 3 and Examples 1 and 2, respectively.
도 13 내지 도 17을 보면 알 수 있듯이, 비교예 1은 초기 용량이 358 mAh/g로 낮게 나타났으나, 수명 성능은 300cycle을 만족하는 것을 확인할 수 있었다(도 13)As can be seen from Figures 13 to 17, Comparative Example 1 showed a low initial capacity of 358 mAh/g, but it was confirmed that the lifespan performance satisfied 300 cycles (Figure 13)
비교예 2는 카본코팅으로 초기 용량이 3250 mAh/g로 우수하게 나타났으나, 수명 성능이 낮게 나타나는 것을 확인할 수 있었다(도 14).In Comparative Example 2, the initial capacity was excellent at 3250 mAh/g with carbon coating, but it was confirmed that the lifespan performance was low (FIG. 14).
비교예 3은 초기 용량이 2000mAh/g로 높게 나타났으나, 수명 성능이 낮게 나타나는 것을 확인할 수 있었다(도 15).In Comparative Example 3, the initial capacity was high at 2000 mAh/g, but it was confirmed that the lifespan performance was low (FIG. 15).
실시예 1은 비교예 2와 비교하여 초기 용량은 다소 떨어졌으나, 수명 성능이 월등하게 좋아진 것을 확인할 수 있었고, 비교예 1과 비교해서는 초기 용량이 크게 증가한 것을 확인할 수 있었다(도 16).In Example 1, the initial capacity was slightly lower compared to Comparative Example 2, but it was confirmed that the lifespan performance was significantly improved, and the initial capacity was confirmed to be significantly increased compared to Comparative Example 1 (FIG. 16).
실시예 2는 산화막과 산화붕소 코팅막이 없는 비교예 2 대비 초기 용량과 수명 성능이 모두 향상된 것을 확인할 수 있었다(도 17).In Example 2, it was confirmed that both the initial capacity and lifetime performance were improved compared to Comparative Example 2 without an oxide film and a boron oxide coating film (FIG. 17).
이상으로 첨부된 도면을 참조하여 본 발명의 실시 예를 설명하였으나, 본 발명의 속하는 기술분야에서 통상의 지식을 가진 자는 본 발명의 기술적 사상이나 필수적인 특징을 변경하지 않고 다른 구체적인 형태로 실시할 수 있다는 것을 이해할 수 있을 것이다. 따라서 이상에서 기술한 실시 예는 모든 면에서 예시적인 것이며 한정적이 아닌 것이다.Although embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art can realize that the present invention can be implemented in other specific forms without changing the technical idea or essential features of the present invention. You will be able to understand it. Therefore, the embodiments described above are illustrative in all respects and are not restrictive.
[부호의 설명] [Explanation of symbols]
1: 판상 실리콘 복합체1: Plate-shaped silicone composite
10: 판상 실리콘10: Plate-shaped silicon
10a: 판상 실리콘 입자10a: plate-shaped silicon particles
11: 산화막11: Oxide film
12: 산화붕소 코팅막12: Boron oxide coating film
13: 카본 코팅막13: Carbon coating film
2: 흑연2: graphite

Claims (9)

  1. 폐실리콘 커프(Silicon kerf)로 형성된 판상 실리콘으로 제조된 판상 실리콘 복합체를 포함하되,Including a plate-shaped silicone composite made of plate-shaped silicon formed from a waste silicon kerf,
    상기 판상 실리콘 복합체는,The plate-shaped silicon composite,
    상기 판상 실리콘을 해쇄하여 형성된 0.1 내지 0.4g/㎤의 겉보기 밀도를 가지는 판상 실리콘 입자;Plate-shaped silicon particles having an apparent density of 0.1 to 0.4 g/cm3 formed by pulverizing the plate-shaped silicon;
    상기 판상 실리콘 입자의 표면을 산화시켜 형성된 산화막;An oxide film formed by oxidizing the surface of the plate-shaped silicon particles;
    상기 산화막이 형성된 판상 실리콘 입자의 표면에 산화붕소를 코팅하여 형성된 산화붕소 코팅막 및A boron oxide coating film formed by coating boron oxide on the surface of the plate-shaped silicon particles on which the oxide film is formed, and
    상기 판상 실리콘 입자 외각에 상기 산화막과 산화붕소 코팅막을 감싸도록 전도성 카본으로 코팅되어 형성된 카본 코팅막을 포함하는 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재.A silicon anode material for a lithium-ion secondary battery to which boron oxide is applied, including a carbon coating film formed by coating the outer shell of the plate-shaped silicon particles with conductive carbon to surround the oxide film and the boron oxide coating film.
  2. 제1항에 있어서,According to paragraph 1,
    상기 판상 실리콘 입자는,The plate-shaped silicon particles,
    상기 판상 실리콘을 습식밀링하고 건조되어 얻어진 것을 특징으로 하는 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재.A silicon anode material for a lithium-ion secondary battery to which boron oxide is applied, which is obtained by wet milling and drying the plate-shaped silicon.
  3. 제1항에 있어서,According to paragraph 1,
    상기 판상 실리콘은,The plate-shaped silicon is,
    평균 두께가 10 내지 100㎚, 평균 길이가 10㎛ 이하인 것을 특징으로 하는 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재.A silicon anode material for a lithium ion secondary battery to which boron oxide is applied, characterized in that the average thickness is 10 to 100 nm and the average length is 10 μm or less.
  4. 제1항에 있어서,According to paragraph 1,
    상기 산화막은,The oxide film is,
    평균 두께가 2 내지 10㎚인 것을 특징으로 하는 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재.A silicon anode material for a lithium ion secondary battery to which boron oxide is applied, characterized in that the average thickness is 2 to 10 nm.
  5. 제1항에 있어서,According to paragraph 1,
    상기 산화막은,The oxide film is,
    상기 판상 실리콘 입자에 산화제를 투입하고 700 내지 1,100℃로 가열하여 형성된 것을 특징으로 하는 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재.A silicon anode material for a lithium-ion secondary battery to which boron oxide is applied, which is formed by adding an oxidizing agent to the plate-shaped silicon particles and heating it to 700 to 1,100°C.
  6. 제1항에 있어서,According to paragraph 1,
    상기 산화붕소 코팅막은,The boron oxide coating film,
    상기 산화막이 형성된 판상 실리콘 입자에 붕산 수용액을 투입하고 550 내지 700℃로 가열하여 형성된 것을 특징으로 하는 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재.A silicon anode material for a lithium ion secondary battery to which boron oxide is applied, which is formed by adding an aqueous solution of boric acid to the plate-shaped silicon particles on which the oxide film is formed and heating it to 550 to 700°C.
  7. 제1항에 있어서,According to paragraph 1,
    상기 카본 코팅막은,The carbon coating film,
    평균 두께가 3 내지 20㎚인 것을 특징으로 하는 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재.A silicon anode material for a lithium ion secondary battery to which boron oxide is applied, characterized in that the average thickness is 3 to 20 nm.
  8. 제1항에 있어서,According to paragraph 1,
    상기 카본 코팅막은,The carbon coating film,
    상기 산화막과 산화붕소 코팅막이 형성된 판상 실리콘 입자에 탄화수소가스, 액화천연가스 및 액화석유가스 중 하나를 선택하여 투입하고, 750 내지 1000℃에서 열분해시켜 형성된 것을 특징으로 하는 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재.A lithium-ion secondary battery using boron oxide, which is formed by selecting one of hydrocarbon gas, liquefied natural gas, and liquefied petroleum gas into the plate-shaped silicon particles on which the oxide film and the boron oxide coating film are formed, and thermally decomposing it at 750 to 1000 ° C. Silicon cathode material.
  9. 제1항에 있어서,According to paragraph 1,
    흑연을 더 포함하는 산화붕소가 적용된 리튬이온이차전지용 실리콘 음극재.Silicon anode material for lithium-ion secondary batteries applied with boron oxide that further contains graphite.
PCT/KR2022/009191 2022-04-27 2022-06-28 Silicon anode material, having boron oxide applied thereto, for lithium ion secondary battery WO2023210867A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
KR1020220052308A KR102454487B1 (en) 2022-04-27 2022-04-27 Silicon anode materials for lithium ion secondary battery to which boron oxide is applied
KR10-2022-0052308 2022-04-27

Publications (1)

Publication Number Publication Date
WO2023210867A1 true WO2023210867A1 (en) 2023-11-02

Family

ID=83599908

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/KR2022/009191 WO2023210867A1 (en) 2022-04-27 2022-06-28 Silicon anode material, having boron oxide applied thereto, for lithium ion secondary battery

Country Status (2)

Country Link
KR (1) KR102454487B1 (en)
WO (1) WO2023210867A1 (en)

Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2016015299A (en) * 2014-06-30 2016-01-28 ティーエムシー株式会社 Silicon fine particle
KR101614016B1 (en) * 2014-12-31 2016-04-20 (주)오렌지파워 Silicon based negative electrode material for rechargeable battery and method of fabricating the same
KR20190083613A (en) * 2018-01-03 2019-07-12 삼성전자주식회사 Silicon-containing structure, carbon composite using the same, electrode, lithium battery, and electronic device
KR20210071110A (en) * 2014-06-11 2021-06-15 닛신 가세이 가부시키가이샤 Negative electrode material for lithium ion batteries, lithium ion battery, method and apparatus for producing negative electrode for lithium ion batteries, and method and apparatus for producing negative electrode material for lithium ion batteries
KR20210152604A (en) * 2020-06-08 2021-12-16 주식회사 엠지이노베이션 Method for manufacturing silicon/non-static oxidized silicon/carbon complex cathodic materials of lithium-ion batteries using discarded silicon sludge

Family Cites Families (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5623262B2 (en) 2010-12-13 2014-11-12 Ｊｘ日鉱日石エネルギー株式会社 Graphite material for negative electrode of lithium ion secondary battery and method for producing the same, lithium ion secondary battery
CN112573530B (en) * 2020-12-18 2022-08-05 四川大学 Sulfur species activated SiO 2 Preparation method of lithium battery negative electrode material

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR20210071110A (en) * 2014-06-11 2021-06-15 닛신 가세이 가부시키가이샤 Negative electrode material for lithium ion batteries, lithium ion battery, method and apparatus for producing negative electrode for lithium ion batteries, and method and apparatus for producing negative electrode material for lithium ion batteries
JP2016015299A (en) * 2014-06-30 2016-01-28 ティーエムシー株式会社 Silicon fine particle
KR101614016B1 (en) * 2014-12-31 2016-04-20 (주)오렌지파워 Silicon based negative electrode material for rechargeable battery and method of fabricating the same
KR20190083613A (en) * 2018-01-03 2019-07-12 삼성전자주식회사 Silicon-containing structure, carbon composite using the same, electrode, lithium battery, and electronic device
KR20210152604A (en) * 2020-06-08 2021-12-16 주식회사 엠지이노베이션 Method for manufacturing silicon/non-static oxidized silicon/carbon complex cathodic materials of lithium-ion batteries using discarded silicon sludge

Also Published As

Publication number Publication date
KR102454487B1 (en) 2022-10-14

Similar Documents

Publication Publication Date Title
WO2018147508A1 (en) Method for preparing silicon-carbon-graphene composite, composite prepared according thereto, and secondary battery to which same is applied
WO2015156446A1 (en) Graphene-metal nanoparticle composite, carbon nanofiber composite containing composite, and secondary battery containing carbon nanoparticle composite
WO2020222628A1 (en) Silicon oxide composite for lithium secondary battery anode material and method for manufacturing same
WO2015065047A1 (en) Negative electrode active material and method for preparing same
WO2020256395A2 (en) Carbon-silicon composite oxide composite for lithium secondary battery anode material, and preparation method therefor
WO2014104842A1 (en) Negative electrode active material for secondary battery, conductive composition for secondary battery, negative electrode material comprising same, negative electrode structure and secondary battery comprising same, and method for manufacturing same
WO2010041907A2 (en) Negative active material for rechargeable lithium battery, method of preparing the same, and rechargeable lithium battery comprising the same
US20040258606A1 (en) Fine carbon fiber, method for producing the same and use thereof
WO2011068389A2 (en) Multicomponent nano composite oxide powder and a preparation method therefor, a fabrication method of an electrode using the same, a thin film battery having the electrode and a fabrication method for the battery
WO2020130443A1 (en) Method for producing negative electrode active material for lithium secondary battery
WO2017074081A1 (en) Siox-fullerene complex, preparation method therefor, preparation apparatus therefor, and use thereof
WO2019177355A1 (en) Ceria-carbon-sulfur composite, method for preparing same, and positive electrode and lithium-sulfur battery comprising same
WO2017209561A1 (en) Cathode active material, cathode comprising same, and lithium secondary battery comprising same
WO2023210867A1 (en) Silicon anode material, having boron oxide applied thereto, for lithium ion secondary battery
WO2017209556A1 (en) Cathode active material, method for preparing same, cathode comprising same, and lithium secondary battery comprising same
WO2023210868A1 (en) Method for preparing silicon anode material for lithium-ion secondary battery
WO2023210866A1 (en) Silicon anode material for lithium ion secondary battery
WO2023210869A1 (en) Method for preparing silicon anode material, for lithium-ion secondary battery, to which boron oxide is applied
WO2022050801A1 (en) Separator for electrochemical device and method for manufacturing same
WO2022060138A1 (en) Negative electrode and secondary battery comprising same
WO2023014126A1 (en) Manufacturing system and method for dry electrode film
WO2021261697A1 (en) Method for reusing active material by using cathode scrap
WO2023068432A1 (en) Negative electrode active material for lithium secondary battery, lithium secondary battery including same, and method for producing same
WO2020179978A1 (en) Secondary battery, fuel cell, separator for secondary battery or fuel cell, and method for manufacturing separator
WO2023106893A1 (en) Fast-charging anode material for lithium secondary battery, and preparing method of lithium secondary battery comprising same

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 22940361

Country of ref document: EP

Kind code of ref document: A1