KR20210108070A - Devices and methods for carbon compounding silicon oxide particle and anode material of silicon oxide particle-carbon composite - Google Patents

Abstract

The present invention relates to a silicon oxide particle carbon complexing method and a device thereof. More specifically, the present invention complexes silicon oxide particles and carbon by using a biaxial extruder in order to manufacture a silicon oxide particle carbon complexed negative electrode material. According to the present invention, a silicon oxide particle carbon complexed negative electrode material can be uniformly manufactured based on a single process.

Description

Silicon oxide particle carbon composite device and method, silicon oxide particle carbon composite anode material

The present invention relates to a method and apparatus for complexing silicon oxide particles with carbon, and more particularly, the present invention is to complex silicon oxide particles and carbon using a twin-screw extruder to prepare a silicon oxide particle carbon composite negative electrode material.

Demand for power storage devices is rapidly increasing, from small electronic devices such as mobile (IT) devices to medium and large devices such as electric vehicles (EVs) and energy storage devices (ESS). In particular, technology development and demand for lithium secondary batteries are rapidly increasing, and lithium secondary batteries having a higher energy density than conventional ones are required. In order to increase the energy density, R&D is being carried out to increase the capacity of the cathode and anode materials, to increase the density of the electrode plate, to reduce the thickness of the separator, and to increase the charge/discharge voltage. is being focused

The negative electrode material of a lithium secondary battery accepts electrons and lithium ions during charging, and emits electrons and lithium ions to the positive electrode during discharging. In order to be used as an anode material, it must have excellent stability, electrical conductivity, low chemical reactivity, price and storage capacity. Natural graphite, artificial graphite, metal-based, carbon-based, and silicon-based materials are used as anode materials, and development of silicon-based materials most advantageous for high capacity is being actively developed. Silicon-based material has a theoretical capacity of 4,200 mAh/g, which is several times higher than the theoretical capacity of 372 mAh/g of graphite-based anode material, so it is attracting attention as a next-generation material to replace the existing anode material. However, the silicon-based material changes its crystal structure as lithium ions are inserted during charging, and it accompanies a volume expansion of about 4 times compared to before lithium is inserted. Therefore, the silicon-based material cannot withstand the volume change as the charging and discharging are repeated, resulting in cracks in the crystal and the destruction of the particles, and the electrical connection between adjacent particles is deteriorated, resulting in deterioration of lifespan characteristics.

In order to improve these drawbacks, studies have been conducted to improve the lifespan characteristics and alleviate the volume expansion using silicon oxide (SiOx), but silicon oxide forms an irreversible product as lithium is inserted, so it depletes lithium to reduce the initial reversible efficiency ( ICE) is low.

Korean Patent Publication No. 10-2022891 Korean Patent Publication No. 10-1939976

The present invention has been devised to solve the above-described problems, and an object of the present invention is to provide a method and apparatus for complexing silicon oxide particles with carbon, complexing and coarsening silicon oxide particles with carbon, and the initial reversible efficiency of a lithium secondary battery and It is to provide a silicon oxide particle carbon composite anode material capable of improving lifespan characteristics.

In addition, by providing a silicon oxide particle carbon composite device and method, it is possible to uniformly manufacture a silicon oxide particle carbon composite negative electrode material in a single process.

Silicon oxide particle carbon composite device according to the present invention is a hopper to which the silicon oxide particles and the pitch is supplied; a twin screw for preparing a composite by mixing the silicon oxide particles and the pitch; and a discharge port for extruding and discharging the composite.

In addition, the hopper is characterized in that graphite is further supplied.

In addition, the twin screw is characterized in that it includes one or more mixing blocks.

In addition, the mixing block, a transport block for transporting the silicon oxide particles and the pitch to the discharge port; and a kneading block for preparing the composite by mixing the silicon oxide particles and the pitch.

In addition, the mixing block, characterized in that the temperature is controlled through the temperature control unit.

In addition, the discharge port, characterized in that it comprises a reverse for controlling the transport speed of the composite.

Silicon oxide particle carbon complexing method according to the present invention is a supply step of supplying the silicon oxide particles and the pitch to the hopper; A mixing step of preparing the composite by mixing the silicon oxide particles and the pitch through a twin screw; and a discharging step of extruding and discharging the composite through a discharging port.

In addition, the supply step is characterized in that the silicon oxide particles and the pitch are stirred in advance and supplied to the hopper.

In addition, the supply step, the softening point of the pitch is characterized in that the supply to the hopper that 95 ℃ to 260 ℃.

In addition, the supply step is characterized in that the silicon oxide particles and the pitch are supplied in a weight ratio of 5:5 to 7:3.

In addition, the supply step, characterized in that further supplying graphite to the hopper.

In addition, the supply step, the silicon oxide particles, the pitch, and the graphite is characterized in that it is supplied in a weight ratio of 1:4:5.

In addition, the mixing step is characterized in that it is performed at a temperature of 100 ℃ to 400 ℃.

In addition, in the mixing step, one or more mixing blocks are included in the twin screw to repeat the mixing step, and the mixing block is characterized in that the temperature is controlled through a temperature control unit.

In addition, the mixing block is composed of a moving block and a kneading block, and transports the silicon oxide particles and the pitch along the transfer block in the axial direction of the twin screw, and the silicon oxide particles and the pitch in the kneading block It is characterized in that the composite is prepared by mixing.

In addition, in the discharging step, it is characterized in that the extrusion amount and the discharge amount are uniformly controlled by adjusting the transport speed of the composite in reverse.

In addition, it is characterized in that the supply step, the mixing step, and the discharging step are repeatedly performed two or more times.

Silicon oxide particle carbon composite negative electrode material according to the present invention is characterized in that it includes the composite prepared according to the silicon oxide particle carbon composite method.

In addition, the composite is characterized in that the silicon oxide particle-pitch (SiOx-Pitch) structure.

In addition, the composite is characterized in that the silicon oxide particle-pitch-graphite (SiOx-Pitch-Graphite) structure.

내지 1200

의 온도에서 열처리하는 것을 특징으로 한다.In addition, the complex

to 1200

It is characterized in that the heat treatment at a temperature of.

In addition, the composite is characterized in that the initial reversible efficiency of the lithium secondary battery is realized by 65% or more.

According to the present invention, there is provided a method and apparatus for complexing silicon oxide particles with carbon, thereby complexing and coarsening silicon oxide particles and carbon, and improving the initial reversible efficiency and lifespan characteristics of a lithium secondary battery.

In addition, by providing an apparatus and method for compounding silicon oxide particles with carbon, there is an effect that a silicon oxide particle carbon composite negative electrode material can be uniformly manufactured in a single process.

1 is a cross-sectional view of a silicon oxide particle carbon composite apparatus 100 according to the present invention.
Figure 2 is a flow chart of the silicon oxide particle carbon complexing method according to the present invention.
Figure 3 (a) is a composite SEM analysis picture of Example 1, Figure 3 (b) is a composite SEM analysis picture of Example 2.
Figure 4 (a) is a graph showing the experimental results of measuring the initial charge and discharge capacity and initial reversible efficiency of Example 1, Figure 4 (b) is an experiment measuring the initial charge and discharge capacity and initial reversible efficiency of Example 2 This is a graph showing the results.
Figure 5 (a) is a composite SEM analysis picture of Example 3, Figure 5 (b) is a composite SEM analysis picture of Example 4.
6(a) is a graph showing the experimental results of measuring the initial charge/discharge capacity and the initial reversible efficiency of Example 3, and FIG. 6(b) is an experiment measuring the initial charge/discharge capacity and the initial reversible efficiency of Example 4 This is a graph showing the results.
Figure 7 (a) is a primary extrusion composite SEM analysis picture of Example 5, Figure 7 (b) is a secondary extrusion composite SEM analysis picture of Example 5, Figure 7 (c) is the third of Example 5 It is a picture of the SEM analysis of the extruded composite.
8 is a graph showing the results of measuring the BET specific surface area and pore size of Example 5;
Figure 9 (a) is a primary extrusion composite FE-SEM analysis of Example 5, Figure 9 (b) is a tertiary extrusion composite FE-SEM analysis photograph of Example 5.
10 is a graph showing the experimental results of measuring the initial charge/discharge capacity and the initial reversible efficiency of Example 5;
Figure 11 (a) is a composite SEM analysis photograph of Example 6, Figure 11 (b) is a composite SEM analysis photograph of Comparative Example 1.
12 is a photograph of the composite FE-SEM analysis of Example 6.
13 is a graph showing experimental results of measuring the initial charge/discharge capacity and initial reversible efficiency of Example 6 and Comparative Example 1. FIG.

The present invention will be described in detail with reference to the accompanying drawings as follows. Here, repeated descriptions and detailed descriptions of well-known functions and configurations that may unnecessarily obscure the gist of the present invention will be omitted. The embodiments of the present invention are provided in order to completely explain the present invention to those of ordinary skill in the art. Accordingly, the shapes and sizes of elements in the drawings may be exaggerated for clearer description.

Throughout the specification, when a part "includes" a certain component, it means that other components may be further included, rather than excluding other components, unless otherwise stated.

Hereinafter, preferred examples are presented to help the understanding of the present invention. However, the following examples are only provided for better understanding of the present invention, and the content of the present invention is not limited by the examples.

1 is a cross-sectional view of a silicon oxide particle carbon composite apparatus 100 according to the present invention.

The silicon oxide particle carbon composite apparatus 100 according to the present invention may include a hopper 10 , a twin screw 20 and a discharge port 30 .

The hopper 10 according to the present invention may provide a space for accommodating the raw material supplied for the silicon oxide particle carbon complexation. Silicon oxide (SiOx) particles and pitch may be supplied as a raw material for carbon complexing of the silicon oxide particles, and graphite may be further supplied. The silicon oxide particles may be supplied in the form of silicon oxide nanoparticles, silicon oxide microparticles or silicon oxide nano-microparticles. Pitch is manufactured by applying heat to petroleum residue in an inert atmosphere, and physical properties such as softening point, yield, and molecular weight distribution of the pitch vary depending on the heat treatment temperature, time, and the presence or absence of additives or catalysts. In the present invention, a pitch having a softening point of 95°C to 260°C is supplied to the hopper 10 . The hopper 10 may supply the silicon oxide particle carbon composite material to the twin screw 20 to be described later in a uniform amount and at a constant speed.

The twin screw 20 according to the present invention may be mixed with silicon oxide particles and pitch to prepare a composite. A hopper 10 is formed on one side of the upper part of the twin-screw 20, and a discharge port 30 through which the composite is extruded and discharged may be formed on the other side. The twin-screw 20 may be manufactured by using the twin-screw 20 in the same or reverse direction, but preferably, a uniform composite may be continuously manufactured using the twin-screw in the same direction.

The twin screw 20 may include one or more mixing blocks 21 . The mixing block 21 may include a transfer block 22 and a kneading block 23 . The transfer block 22 may transfer the silicon oxide particles and the pitch to the discharge port 30, and the kneading block 23 may mix the silicon oxide particles and the pitch passed through the transfer block 22 to prepare a composite. . When the silicon oxide particles and the pitch pass through the transfer block 22 and the kneading block 23, the organic material is excessively vaporized in the pitch and it is difficult to maintain the molded state of the composite, so the transfer block 22 and the kneading block 23 By arranging a plurality in succession, excessive torque generation can be suppressed. At this time, the excessively vaporized organic material may be discharged through a vent hole (not shown) of the housing 40 surrounding the twin screw 20 .

As shown in FIG. 1, the mixing block 21 may be arranged in areas A to E on the twin-screw 20 alternately with the transfer block 22 and the kneading block 23, but must be limited to this arrangement order it's not going to be The number of mixing blocks 21 is not limited, but it is preferable to alternately arrange the transfer block 22 and the kneading block 23 to include at least two or more.

On the other hand, in the regions A to E of the mixing block 21 disposed on the twin screw 20, each temperature can be controlled through a temperature control unit (not shown), so the AE of the mixing block 21 according to the process conditions The temperature of each area can be set differently.

In addition, the screw intersection ratio of the twin-screw 20, D _o /D _i value is not particularly limited, but is preferably 28 to 40. Here, D _o is an Out Diameter value _{of the screw, and D i} is an In Diameter value of the screw. D If _o / D _i value of 28 is less than not performed sufficiently mixing of the silicon oxide particle and the pitch load on the discharge port 30 if it is possible to reduce the extrusion efficiency, than the D _o / D _i value is 40 There may be a problem in that the discharge port 30 is damaged due to excessive .

The discharge port 30 according to the present invention can extrude and discharge the composite manufactured by the twin screw 20 .

A reverse 31 may be included at the front end of the discharge port 30 . Reverse 31 can prevent the load of the discharge port 30 by adjusting the transport speed of the composite manufactured in the mixing block 21 . The composite passing through the reverse 31 may be extruded and discharged in the cross-sectional shape of the discharge port 30 .

Figure 2 is a flow chart of the silicon oxide particle carbon complexing method according to the present invention.

The silicon oxide particle carbon complexing method according to the present invention may include a supplying step (S10), a mixing step (S20) and a discharging step (S30). The silicon oxide particle carbon complexing method may be performed by the silicon oxide particle carbon complexing apparatus 100 according to the present invention.

The supply step (S10) according to the present invention may supply the silicon oxide particles and the pitch to the hopper (10). At this time, it is possible to improve the quality of the composite manufactured by stirring the silicon oxide particles and the pitch in advance, and supplying it to the hopper 10 in a uniform amount.

At this time, the pitch provides that the softening point is 95 ℃ to 260 ℃. If the softening point of the pitch is less than 95 ℃, there occurs a problem that the capacity retention rate of the lithium secondary battery is reduced due to the low carbon content. If the softening point of the pitch exceeds 260 ℃, there may be a problem that it is difficult to uniformly mix the silicon oxide particles and the pitch.

Silicon oxide particles and pitch are supplied in a weight ratio of 5:5 to 7:3. When the weight ratio of the silicon oxide particles to the pitch does not satisfy the weight ratio of 5:5 to 7:3, the capacity of the lithium secondary battery is not sufficiently improved.

In addition, graphite may be further supplied in the supply step ( S10 ). At this time, by supplying the silicon oxide particles, pitch and graphite in a weight ratio of 1:4:5, it is possible to improve the capacity and capacity retention rate of the lithium secondary battery.

In the mixing step (S20) according to the present invention, the composite can be prepared by mixing the silicon oxide particles and the pitch through the twin screw 20. The twin screw 20 includes one or more mixing blocks 21 to repeatedly perform the mixing step (S20), and the mixing block 21 may have a manufacturing temperature controlled through a temperature control unit (not shown).

The mixing block 21 may be composed of a transfer block 22 and a kneading block 23 . In the mixing step (S20), the silicon oxide particles and pitch, which are raw materials, are transferred along the transfer block 20 in the axial direction from the twin screw 20 to the outlet 30 side, and the silicon oxide particles and the pitch in the kneading block 23 can be mixed to prepare a composite.

The mixing step (S20) may be performed at a temperature of 100° C. to 400° C. in order to mix the silicon oxide particles and pitch, which are raw materials for manufacturing the composite, in a liquid state. If the temperature is less than 100 ℃, the raw material is hardened in the middle of the composite manufacturing process, a phenomenon that the twin-screw 20 and the discharge port 30 are clogged occurs. When the temperature exceeds 400 ° C., the composite is not extruded and a leaking phenomenon may occur, or a problem may occur in which the viscosity of the composite increases due to depletion of oil.

In the discharging step (S30) according to the present invention, the composite prepared in the mixing step (S20) may be extruded and discharged through the discharge port 30 . Before the composite is extruded and discharged from the outlet 30 , the transport speed of the composite is adjusted in the reverse 31 , thereby uniformly controlling the extrusion amount and discharge of the composite.

In the silicon oxide particle carbon composite method according to the present invention, the supply step (S10), the mixing step (S20) and the discharging step (S30) are repeatedly performed two or more times so that the composite can be uniformly extruded.

The silicon oxide particle carbon composite negative electrode material according to the present invention may include a composite prepared according to the silicon oxide particle carbon composite method. The composite may satisfy a silicon oxide particle-pitch (SiOx-Pitch) structure or a silicon oxide particle-pitch-graphite (SiOx-Pitch-Graphite) structure. The composite of silicon oxide particle-pitch-graphite structure has a uniform structure in which silicon oxide particles are disposed between graphite layers.

The manufactured composite may be subjected to heat treatment at a temperature of 650° C. to 1200° C. to remove low-boiling-point substances of the pitch remaining in the composite. The pitch from which the low boiling point is removed may have excellent pore properties. When the heat treatment is performed at less than 650° C., the low boiling point substances are not sufficiently removed. When the heat treatment is performed at a temperature of more than 1200° C., cracks occur in the composite, resulting in a problem of quality deterioration.

When the prepared composite is applied to the negative electrode of the lithium secondary battery to measure the electrochemical properties, the initial reversible efficiency of the lithium secondary battery can be realized by 65% or more.

<Example 1>

Example 1 is a composite prepared by mixing silicon oxide particles and pitch having a softening point of 260° C. in a weight ratio of 5:5. At this time, the temperature of the A region of the twin-screw screw was 250 °C, the temperature of the B to E region was 300 °C, and the temperature of the outlet was 330 °C.

<Example 2>

Example 2 is a composite prepared by mixing silicon oxide particles and pitch having a softening point of 260° C. in a weight ratio of 7:3. At this time, the temperature of the A region of the twin-screw screw was 250 °C, the temperature of the B to E region was 300 °C, and the temperature of the outlet was 330 °C.

L/L
(mm/cm ² ) Initial charge capacity (mAh/g) Initial discharge capacity (mAh/g) Initial reversible efficiency
(%) Example 1 2.70 1359 938 69.0 Example 2 2.62 1454 1024 70.4

Figure 3 (a) is a composite SEM analysis picture of Example 1, Figure 3 (b) is a composite SEM analysis picture of Example 2.

Figure 4 (a) is a graph showing the experimental results of measuring the initial charge and discharge capacity and initial reversible efficiency of Example 1, Figure 4 (b) is an experiment measuring the initial charge and discharge capacity and initial reversible efficiency of Example 2 This is a graph showing the results.

Referring to Table 1 and FIG. 4, a composite having an initial reversible efficiency of a lithium secondary battery of 65% or more was prepared. When the softening point of the pitch is 260° C., it can be seen that Example 2 having a larger weight ratio of silicon oxide particles has better initial charge/discharge capacity and initial reversible efficiency than Example 1.

<Example 3>

Example 3 is a composite prepared by mixing silicon oxide particles and a pitch having a softening point of 120° C. in a weight ratio of 5:5. At this time, the temperature of the A region of the twin-screw screw was 310 °C, the temperature of the B to E region was 300 °C, and the temperature of the outlet was mixed under the conditions of 280 °C.

<Example 4>

Example 4 is a composite prepared by mixing silicon oxide particles and a pitch having a softening point of 120° C. in a weight ratio of 7:3. At this time, the temperature of the A region of the twin-screw screw was 310 °C, the temperature of the B to E region was 300 °C, and the temperature of the outlet was mixed under the conditions of 280 °C.

L/L
(mm/cm ² ) Initial charge capacity (mAh/g) Initial discharge capacity (mAh/g) Initial reversible efficiency
(%) Example 3 2.81 1714 1207 70.4 Example 4 2.81 1732 1205 69.6

Figure 5 (a) is a composite SEM analysis photograph of Example 3, Figure 5 (b) is a composite SEM analysis photograph of Example 4.

6(a) is a graph showing the experimental results of measuring the initial charge/discharge capacity and the initial reversible efficiency of Example 3, and FIG. 6(b) is an experiment measuring the initial charge/discharge capacity and the initial reversible efficiency of Example 4 This is a graph showing the results.

Referring to Table 2 and FIG. 6 , a composite having an initial reversible efficiency of 65% or more of a lithium secondary battery was prepared. When the softening point of the pitch is 120° C., it can be confirmed that Example 3, in which the weight ratio of silicon oxide particles is smaller, has a smaller initial charging capacity compared to Example 4, but has excellent initial reversible efficiency and thus a larger initial discharge capacity.

<Example 5>

Example 5 is a composite prepared by mixing silicon oxide particles and a pitch having a softening point of 120° C. in a weight ratio of 4:3. Before supplying the silicon oxide particles and pitch, they were pre-stirred in a powder mixer device, and then supplied to the silicon oxide particle carbon complexing device. At this time, the temperature of the A region of the twin screw was 250 °C, the temperature of the B to E region was 300 °C, and the temperature of the outlet was 280 °C.

BET
Specific surface area (m ² /g) pore size
(Å) L/L
(mm/cm ² ) Initial charge capacity (mAh/g) Initial discharge capacity (mAh/g) Initial reversible efficiency
(%) 1st extrusion 31.057 195.5 2.61 1699 1179 69.4 secondary extrusion 31.448 189.1 2.54 1831 1260 68.8 3rd Extrusion 29.631 205.4 2.03 1652 1122 67.9

Figure 7 (a) is a primary extrusion composite SEM analysis picture of Example 5, Figure 7 (b) is a secondary extrusion composite SEM analysis picture of Example 5, Figure 7 (c) is the third of Example 5 It is an extruded composite SEM analysis picture.

8 is a graph showing the results of measuring the BET specific surface area and pore size of Example 5;

Figure 9 (a) is a primary extrusion composite FE-SEM analysis of Example 5, Figure 9 (b) is a tertiary extrusion composite FE-SEM analysis photograph of Example 5.

10 is a graph showing the experimental results of measuring the initial charge/discharge capacity and the initial reversible efficiency of Example 5.

Referring to FIGS. 7 and 9 , it can be seen that the silicon is locally agglomerated in the first and second extrusion composites of Example 5. This means that silicon is agglomerated due to insignificant uniform mixing in the axial or longitudinal direction during extrusion. At least 3rd extrusion eliminates the aggregation of silicon in the composite and produces a composite with a uniform distribution.

Referring to FIG. 10 and Table 3, in the case of the composite subjected to the tertiary extrusion, a composite having a uniform distribution was prepared, and it can be confirmed that the uniformity and electrochemical properties were improved compared to the composite of the first extrusion and the second extrusion.

<Example 6>

Example 6 is a composite prepared by mixing silicon oxide particles, pitch and graphite having a softening point of 120° C. in a weight ratio of 1:4:5. At this time, the temperature of the A region of the twin screw was 140 ℃, the temperature of the B to E region was 260 ℃, and the temperature of the outlet was mixed under the conditions of 210 ℃.

<Comparative Example 1>

Comparative Example 1 is a composite prepared by mixing pitch and graphite having a softening point of 120° C. in a weight ratio of 5:5. At this time, the temperature of the A region of the twin-screw screw was 130 °C, the temperature of the B to E region was 250 °C, and the temperature of the outlet was 200 °C.

BET
Specific surface area (m ² /g) pore
size
(Å) L/L
(mm/cm ² ) Initial charge capacity (mAh/g) Initial discharge capacity (mAh/g) Initial reversible efficiency
(%) Volume
retention rate
(100 cycles, %) Example 6 2.777 1733.05 2.51 545 414 76.0 99.9 Comparative Example 1 2.848 153.82 2.55 440 339 77.0 102.5

Figure 11 (a) is a composite SEM analysis photograph of Example 6, Figure 11 (b) is a composite SEM analysis photograph of Comparative Example 1.

12 is a photograph of the composite FE-SEM analysis of Example 6.

13 is a graph showing experimental results of measuring the initial charge/discharge capacity and initial reversible efficiency of Example 6 and Comparative Example 1. FIG.

Referring to FIG. 12 , it can be seen that the silicon oxide particles are disposed between the graphite layers in Example 6.

Referring to FIG. 13 and Table 4, it can be seen that the initial charge capacity of Example 6 is improved by 105 mAh/g compared to Comparative Example 1. Through this, it can be confirmed that the capacity of the lithium secondary battery is improved in Example 6 in which both silicon oxide particles, pitch, and graphite are mixed than in Comparative Example 1 in which only pitch and graphite are mixed.

Although described with reference to the preferred embodiments of the present invention, those of ordinary skill in the art can variously modify and change the present invention within the scope without departing from the spirit and scope of the present invention described in the claims below. You will understand that it can be done.

100: silicon oxide particle carbon complexing device
10: Hopper
20: twin screw
21: mixing block
22: transfer block
23: kneading block
30: outlet
31: reverse
40: housing

Claims (22)

a hopper to which silicon oxide particles and pitch are supplied;
a twin screw for preparing a composite by mixing the silicon oxide particles and the pitch; and
A discharge port for extruding and discharging the composite; characterized in that it comprises,
Silicon oxide particle carbon complexing device.
The method of claim 1,
The hopper is
Characterized in that graphite is further supplied,
Silicon oxide particle carbon complexing device.
The method of claim 1,
The twin screw is
Characterized in comprising one or more mixing blocks,
Silicon oxide particle carbon complexing device.
4. The method of claim 3,
The mixing block is
a transfer block for transferring the silicon oxide particles and the pitch to the outlet; and
A kneading block for producing the composite by mixing the silicon oxide particles and the pitch; characterized in that it comprises,
Silicon oxide particle carbon complexing device.
4. The method of claim 3,
The mixing block is
characterized in that the temperature is controlled through a temperature control unit,
Silicon oxide particle carbon complexing device.
The method of claim 1,
The outlet is
Characterized in that it comprises a reverse for controlling the transport speed of the composite,
Silicon oxide particle carbon complexing device.
A supply step of supplying silicon oxide particles and pitch to the hopper;
A mixing step of preparing the composite by mixing the silicon oxide particles and the pitch through a twin screw; and
A discharging step of extruding and discharging the composite through a discharging port; characterized in that it comprises,
Silicon oxide particle carbon complexing method.
8. The method of claim 7,
The supply step is
Characterized in that the silicon oxide particles and the pitch are stirred in advance and supplied to the hopper,
Silicon oxide particle carbon complexing method.
8. The method of claim 7,
The supply step is
Characterized in that the softening point of the pitch is supplied to the hopper of 95 ℃ to 260 ℃,
Silicon oxide particle carbon complexing method.
8. The method of claim 7,
The supply step is
Characterized in that the silicon oxide particles and the pitch are supplied in a weight ratio of 5:5 to 7:3,
Silicon oxide particle carbon complexing method.
8. The method of claim 7,
The supply step is
Characterized in that further supplying graphite to the hopper,
Silicon oxide particle carbon complexing method.
12. The method of claim 11,
The supply step is
Characterized in that the silicon oxide particles, the pitch and the graphite are supplied in a weight ratio of 1:4:5,
Silicon oxide particle carbon complexing method.
8. The method of claim 7,
The mixing step is
Characterized in that it is carried out at a temperature of 100 ℃ to 400 ℃,
Silicon oxide particle carbon complexing method.
8. The method of claim 7,
The mixing step is
One or more mixing blocks are included in the twin screw to repeat the mixing step,
The mixing block is characterized in that the temperature is controlled through a temperature control unit,
Silicon oxide particle carbon complexing method.
15. The method of claim 14,
The mixing block is composed of a moving block and a kneading block,
Transferring the silicon oxide particles and the pitch along the transfer block in the axial direction of the twin-screw,
Characterized in that by mixing the silicon oxide particles and the pitch in the kneading block to prepare the composite,
Silicon oxide particle carbon complexing method.
8. The method of claim 7,
The discharging step is
Characterized in that by controlling the feed rate of the composite in reverse to uniformly control the extrusion amount and discharge amount,
Silicon oxide particle carbon complexing method.
8. The method of claim 7,
characterized in that the supply step, the mixing step and the discharging step are repeatedly performed two or more times,
Silicon oxide particle carbon complexing method.
The silicon oxide particle carbon complexing method according to claim 7, characterized in that it comprises the composite prepared by the method,
Silicon oxide particle carbon composite negative electrode material.
19. The method of claim 18,
The complex is
Silicon oxide particle-pitch (SiOx-Pitch) characterized in that the structure,
Silicon oxide particle carbon composite negative electrode material.
19. The method of claim 18,
The complex is
Silicon oxide particle-pitch-graphite (SiOx-Pitch-Graphite) characterized in that the structure,
Silicon oxide particle carbon composite negative electrode material.
19. The method of claim 18,
650 the complex

to 1200

characterized in that heat treatment at a temperature of
Silicon oxide particle carbon composite negative electrode material.
19. The method of claim 18,
The complex is
Characterized in that the initial reversible efficiency of the lithium secondary battery is realized more than 65%,
Silicon oxide particle carbon composite negative electrode material.

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