Diverging and stirring barrel for silicon-based negative electrode material

Abstract

The utility model discloses a silicon-based cathode material dispersing and stirring barrel, which is characterized in that a material mixing pipe is arranged at the bottom of a barrel body, a stirring shaft is coaxially arranged in the material mixing pipe, the end part of the stirring shaft extends and penetrates through the side wall of the barrel body and is driven by a first motor, and a spiral blade is fixed on the part of the stirring shaft corresponding to the interior of the material mixing pipe; a feeding pipe is communicated with the upper side of the mixing pipe, a discharging device is installed at a pipe opening in the upper end of the feeding pipe, and the axis of the mixing pipe is internally cut at the bottom of the barrel body. And adding the graphene modified silicon particles, graphite, single-walled carbon nanotubes and carbon black into the slurry in proportion. The silicon-based negative electrode material prepared by the preparation method disclosed by the utility model not only can remarkably improve the conductivity and the initial coulombic efficiency of the silicon-based negative electrode material, but also can maintain relatively high capacity retention ratio and energy density, is highly compatible with the existing battery production process, and provides an economical and efficient novel negative electrode material solution for the lithium ion battery manufacturing industry.

Description

TECHNICAL FIELD

[0001] The utility model belongs to electrode material preparation equipment technical field, especially be related to silicon-based negative electrode material dispersion stirring barrel. BACKGROUND

[0002] The application of silicon-based raw materials as negative electrode materials for lithium-ion batteries has problems of low electrical conductivity and poor initial coulomb efficiency. In the field of lithium-ion batteries, the selection and optimization of negative electrode materials are crucial for improving battery performance. Traditional lithium-ion batteries mostly use graphite as negative electrode materials, but due to its relatively low specific capacity (about 372 mAh / g), silicon-based materials have attracted widespread attention due to their high specific capacity (about 3800-4200 mAh / g).

[0003] However, the application of silicon-based negative electrode materials faces many challenges, mainly including its low electrical conductivity, large expansion rate and low initial coulomb efficiency due to the formation of a solid electrolyte interphase layer during the first charge and discharge. Silicon is mixed with other materials, especially graphite, to take advantage of the high electrical conductivity and good cycle stability of graphite. Both silicon particles and graphite particles are powders, which are easy to mix and disperse, but when added to negative electrode slurry, the powders are prone to clumping after stirring due to the high viscosity coefficient of the negative electrode slurry. SUMMARY

[0004] The purpose of the utility model is to provide a silicon-based negative electrode material dispersion stirring barrel to solve the problem of clumping of silicon particles and graphite particles mixed powder when added to negative electrode slurry.

[0005] To solve the above technical problems, the utility model is realized by the following technical solutions:

[0006] The silicon-based negative electrode material dispersion stirring barrel comprises a barrel body, a mixing pipe is installed at the bottom of the barrel body, a stirring shaft is coaxially installed in the mixing pipe, the end of the stirring shaft extends through the side wall of the barrel body and is driven by a first motor, and helical blades are fixed to the part of the stirring shaft corresponding to the mixing pipe;

[0007] A feeding pipe is communicated with the upper side of the mixing pipe, the upper end of the feeding pipe extends to the opening side of the upper side of the barrel body, a discharging device is installed on the upper end of the feeding pipe, and the axis of the mixing pipe is cut into the bottom of the barrel body.

[0008] Further, the discharging device comprises a second motor installed above the feeding pipe, a spiral feeder is coaxially arranged on the output end of the second motor, and the spiral feeder is sleeved on the feeding pipe.

[0009] A feeding funnel is installed on the upper end of the feeding pipe, and the second motor is supported above the funnel by a support.

[0010] Further, the two mixing pipes are in V-shaped distribution, the butt joint sections of the two mixing pipes are arc-shaped pipe transitions, the two mixing pipes are each provided with a stirring shaft and a spiral blade, the butt joint ends of the two stirring shafts are provided with universal shafts for synchronous rotation, and the pipe openings on the two sides of the mixing pipes are each provided with a shaft sleeve for sleeving the stirring shaft.

[0011] The utility model discloses the following beneficial effects: introduce single -walled carbon nanotube and carbon black as combined conductive agent, and sodium carboxymethyl cellulose and polyacrylic acid as combined binder, effectively solve the volume expansion problem of silicon-based material in the process of charge and discharge. Dissolve sodium carboxymethyl cellulose and polyacrylic acid in deionized water as binder, then add graphene modified silicon particles, graphite, single -walled carbon nanotube and carbon black into the slurry in proportion. Not only can the conductivity and initial coulomb efficiency of silicon-based negative electrode material be improved significantly, but also the capacity retention rate and energy density can be kept high, and the existing battery production process is highly compatible, which provides an economical and efficient new negative electrode material solution for lithium ion battery manufacturing industry. BRIEF DESCRIPTION OF DRAWINGS

[0012] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the following will introduce the drawings needed for the embodiment description.

[0013] Figure 1 The utility model discloses a structure schematic diagram.

[0014] Figure 2 The utility model discloses a spiral feeder split structure schematic diagram.

[0015] Figure 3 The utility model discloses a mixing pipe dismounting structure schematic diagram.

[0016] In the drawings, the components represented by each reference numeral are listed as follows: barrel 1, mixing pipe 2, stirring shaft 31, first motor 3, spiral blade 32, feeding pipe 4, second motor 5, spiral feeder 51, hopper 41, universal shaft 33, shaft sleeve 21. DETAILED DESCRIPTION

[0017] The technical scheme in the embodiments of the utility model will be described clearly and completely in combination with the drawings in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all the embodiments.

[0018] As Figures 1-2As shown: silicon-based negative electrode material dispersion stirring barrel, including barrel 1, barrel is cylindrical barrel, upper side is open side, bottom has a column for support, for containing negative electrode slurry, barrel 1 bottom is provided with mixing pipe 2, mixing pipe is the pipe body with circular cross section, mixing pipe 2 is coaxially provided with stirring shaft 31, stirring shaft 31 end extends through barrel 1 side wall, and is driven by first motor 3, stirring shaft 31 corresponds to the part in mixing pipe 2 and is fixed with spiral blade 32;

[0019] Mixing pipe 2 upper side is communicated with feeding pipe 4, feeding pipe 4 upper end extends to barrel 1 upper side opening side, feeding pipe 4 upper end pipe orifice is provided with discharging device, mixing pipe 2 axis is cut in barrel 1 bottom.

[0020] Through the first motor drive stirring shaft rotates along the axis, spiral blade sleeve is connected to the mixing pipe, and the blade edge is close to the mixing pipe inner side wall, by cooperating with the mixing pipe, the mixing pipe corresponding to the barrel bottom forms a one-way drive device, the negative electrode slurry is stirred by the one end pipe orifice of the mixing pipe, and is discharged by the other end pipe orifice, and the negative electrode slurry is accelerated. And the mixing pipe is close to the bottom of the barrel, and the one-way driving force is formed to make the negative electrode slurry occur one-way spiral stirring.

[0021] In the process of driving negative electrode slurry by mixing pipe, the feeding pipe is communicated, the feeding pipe is close to the feeding end pipe orifice of the mixing pipe, the feeding pipe adds powder, which is mixed graphite powder and silicon powder, into the mixing pipe, and the powder can be uniformly dispersed in the negative electrode slurry under the action of rotating stirring of spiral blade, so that the powder agglomeration phenomenon is reduced.

[0022] As shown in Figure 3 The discharging device includes the second motor 5 installed above the feeding pipe 4, the second motor 5 is coaxially provided with the spiral feeder 51 at the output end, and the spiral feeder 51 is sleeved with the feeding pipe 4. The spiral feeder axis position is the rotating shaft, the rotating shaft side wall is the spiral rotating blade, the discharging rate of the spiral feeder is adjusted by controlling the rotating speed of the second motor, the powder is orderly and slowly added into the negative electrode slurry, the powder is dispersed and opened during the feeding process, and the powder is prevented from being in contact with the negative electrode slurry. The upper end of the feeding pipe 4 is provided with a feeding funnel 41, and the second motor 5 is supported above the funnel 41 by a support.

[0023] As shown in Figure 3 The two mixing pipes 2 are V-shapedly distributed, the butt joint sections of the two mixing pipes 2 are arc-shaped pipe transitions, the two mixing pipes 2 are provided with stirring shafts 31 and spiral blades 32, the butt joint ends of the two stirring shafts 31 are provided with universal shafts 33 for synchronous rotation. The two mixing pipes are arranged close to the inner side wall of the mixing pipe for better forming vortex stirring mode in the barrel. The pipe orifices on both sides of the mixing pipe 2 are provided with shaft sleeves 21 for sleeving the stirring shaft 31. The rotating stability of the stirring shaft is improved.

[0024] The embodiments are selected and specifically described in the specification in order to better explain the principles and practical application of the present application, so that those skilled in the art can well understand and utilize the present application.

Claims

1. A silicon-based anode material dispersion tank characterized by: The utility model relates to a mixing barrel, which comprises a barrel (1) with a mixing pipe (2) installed at the bottom, a stirring shaft (31) coaxially installed in the mixing pipe (2), the stirring shaft (31) extending through the side wall of the barrel (1) at the end and being driven by a first motor (3), and helical blades (32) fixed to the stirring shaft (31) corresponding to the mixing pipe (2). A feeding pipe (4) is connected to the upper side of the mixing pipe (2), the upper end of the feeding pipe (4) extending to the opening side of the barrel (1), a discharging device installed at the upper end of the feeding pipe (4), and the axis of the mixing pipe (2) being cut into the bottom of the barrel (1).

2. The silicon-based anode material dispersion tank according to claim 1, wherein: The discharging device comprises a second motor (5) installed above the feeding pipe (4), a spiral feeder (51) coaxially arranged at the output end of the second motor (5), and the spiral feeder (51) being sleeved with the feeding pipe (4).

3. The silicon-based anode material dispersion tank of claim 2, wherein: A feeding funnel (41) is installed at the upper end of the feeding pipe (4), and the second motor (5) is supported above the funnel (41) by a support.

4. The silicon-based anode material dispersion tank of claim 1, wherein: The mixing pipe (2) is V-shaped, the jointing section of the two mixing pipes (2) is an arc-shaped pipe, and the two mixing pipes (2) are both provided with the stirring shaft (31) and the helical blades (32), the jointing end of the two stirring shafts (31) is provided with a universal shaft (33) for synchronous rotation.

5. The silicon-based anode material dispersion tank according to claim 1 or 4, wherein: The mixing pipe (2) is provided with a shaft sleeve (21) at the pipe opening side of each side for sleeving the stirring shaft (31).

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