Patent Application
20240009676
This application claims all benefits under 35 U.S.C. § 119 from the Chinese Patent Application No. 202210811342.6, filed on Jul. 11, 2022, in the China National Intellectual Property Administration, the disclosure of which is incorporated herein by reference.
The present application relates to a horizontal grinder rotor, grinding bead driving device, and horizontal grinder.
In carbon-based negative active materials, a solid electrolyte interface (SEI layer) is formed on a surface of the carbon-based negative active material during an initial charge or discharge process (the activation process), which can lead to an initial irreversibility. At the same time, the SEI layer can continue to disintegrate and reform in a subsequent charge and discharge process, and the electrolyte can be consumed, thus a battery capacity and cycle performance are reduced. Although silicon exhibits a high gram capacity of 4200 mAh g−1, a volume expansion rate of silicon can reach more than 300% with cycling, which can exacerbate problems caused by the formation of the SEI layer, by destroying electrode structures, increasing internal resistances of batteries and increasing electrolyte side reactions.
In order to overcome the problem of volume expansion, a nanization of materials can be provided to reduce the volume expansion. A conventional method of preparing nano-silicon particles is by grinding which the nano-silicon particles can be manufactured in large quantities at low cost. Horizontal grinders has wide applicability in the grinding method. However, during the process of silicon material processing, the thickening of the silicon slurry can make the horizontal grinders difficult to continue grinding the slurry, thereby not achieving optimal particle sizes.
At present, the horizontal grinders are generally disc structures or disc-like structures. Under a power drive, a main shaft and a disc of the horizontal grinder rotate at a high speed, grinding beads are driven to rotate, collide and roll materials to break particles. However, a liner velocity of the grinding beads in the area between the discs may be slow and the kinetic energy poor, and the grinding effect not good.
When the horizontal grinder is grinding silicon slurry, the solid content rate is difficult to exceed 10%. Since thickening of the silicon slurry cannot be avoided, the solid content rate and the filling rate of the grinding beads are limited. When the silicon slurry thickens, it is necessary to use rotors to continuously drive the slurry for grinding. Currently, the horizontal grinder generally uses zirconia or silicon carbide rotors. However, once the zirconia or silicon carbide rotors crack, the grinding processes stop. Due to the high price of the silicon-carbon composite material, if the rotors crack during processing, it can cause a large production loss. Although the rotors can be replaced regularly, the rotors are quite expensive, which can increase the cost of equipment spare parts.
Therefore, there is room for improvement in the art.
In order to illustrate the technical solutions of the embodiments of the present application more clearly, the accompanying drawings in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present application, and therefore should not be seen as the limiting the scope. For one of ordinary skill in the art, other related drawings can also be obtained from these drawings without any creative work.
Implementations of the present technology will now be described, by way of embodiments, with reference to the attached figures, wherein:
It will be appreciated that for simplicity and clarity of illustration, where appropriate, reference numerals have been repeated among the different figures to indicate corresponding or analogous elements. In addition, numerous specific details are set forth in order to provide a thorough understanding of the embodiments described herein. However, it will be understood by those of ordinary skill in the art that the embodiments described herein can be practiced without these specific details. In other instances, methods, procedures, and components have not been described in detail so as not to obscure the related relevant feature being described. The drawings are not necessarily to scale, and the proportions of certain parts may be exaggerated better illustrate details and features. The description is not to be considered as limiting the scope of the embodiments described herein.
The term “outside” refers to a region that is beyond the outermost confines of a physical object. The term “inside” indicates that at least a portion of a region is partially contained within a boundary formed by the object. The term “substantially” is defined to essentially conforming to the particular dimension, shape or other word that substantially modifies, such that the component need not be exact. For example, substantially cylindrical means that the object resembles a cylinder, but can have one or more deviations from a true cylinder. The term “comprising” means “including, but not necessarily limited to”; it specifically indicates open-ended inclusion or membership in a so-described combination, group, series and the like. It should be noted that references to “an” or “one” embodiment in this disclosure are not necessarily to the same embodiment, and such references mean at least one.
Referring to
The multiple blades 12 are located between the grinding ring 11 and the central body 13. Each blade of the multiple blades 12 is arranged at intervals, thus the structure of the multiple blades 12 is hollow. Each two blades of the multiple blades 12 are in pairs, and the two blades in pairs are symmetrical with respect to the central body 13. A number of the blades of the multiple blades 12 is an even number, which can be two, four, six, eight or the like. A through hole 130 is defined in the center of the central body 13, and two keyways 131 are oppositely arranged on an inner wall of the through hole 130. The through hole 130 and the two keyways 131 are configured to mount the horizontal grinder rotor 10 to a grinder shaft. One or more pins 120 are arranged on one or both sides of each blade of the multiple blades 12. The shape of the pin 120 is not limited, it can be a cylindrical protrusion, or other shapes. The number of the pins 120 can be adjusted according to the strength of the blades and the size and the volume of a horizontal grinder. There is a plurality of latches 132 arranging on the central body 13 close to the blades 12. Each latch of the plurality of latches 132 is arranged on a part of the central body 13 close to each blade 12. The plurality of latches 132 are configured to mount the horizontal grinder rotor 10 to another rotor.
In one embodiment, there are four blades in the multiple blades 12, and there are three pins 120 arranged on each blade of the multiple blades 12. In one embodiment, the pin 120 is a cylindrical protrusion. In one embodiment, the material of the cladding layer is PTEE, and the material can avoid production pollution.
In the horizontal grinder rotor 10, the interval arrangement of the multiple blades 12 can increase the agitation ability of high solid content slurries. There are pins on the blades, which can increase the effective collision probability of grinding beads and increase their linear speed. The design of the multiple blades 12 symmetrically arranged in pairs relative to the center body 13 can be applied to vortex waterwheel, which can increase the fluidity and vortex of the slurries when the viscosity rises. Therefore, the horizontal grinder rotor 10 can grind silicon materials with a solid content greater than 15%. The horizontal grinder rotor 10 can be printed with 3D printing technology, and then coated with a cladding layer, which can prolong the life. Even if a part of the cladding layer peels off, since the silicon carbon material still need to be sintered, the exfoliation of the coating material does not affect the characteristics of the silicon carbon material, thus the horizontal grinder rotor 10 can be replaced regularly to maintain production quality. The material of the horizontal grinder rotor 10 can be high-strength plastic steel material (such as ABS), artificial ceramics, carbon fiber, which can withstand a speed of more than 2600 rpm.
Referring to
In one embodiment, there are three groups of horizontal grinder rotors 10 mounted on the rotating shaft 21, each group of horizontal grinder rotors 10 is arranged at intervals, each group of horizontal grinder rotors comprises two horizontal grinder rotors 10, and the two horizontal grinder rotors 10 are fixed by latches 132. In the projection of the two horizontal grinder rotors 10, the blade of one horizontal grinder rotor is located between two adjacent blades of the other horizontal grinder rotor 10. That is, the blades 12 of the two horizontal grinder rotors 10 are arranged at equal intervals. The pins 120 are only arranged on one side of the blades 12 of each horizontal grinder rotor 10.
The multiple groups of the horizontal grinder rotors 10 comprises at least two groups of the horizontal grinder rotors 10, each group of the horizontal grinder rotors 10 comprises at least two horizontal grinder rotors 10. And the two horizontal grinder rotors 10 are fixed by latches 132 or other methods. The pins can only locate on one side of the blades of each horizontal grinder rotor. Furthermore, if the interference can be avoided, it is better to set pins on both sides of each blade.
A third embodiment of a horizontal grinder (not shown) is provided. The horizontal grinder comprises a grinding cylinder and the grinding bead driving device 20. The grinding cylinder defines an inlet and an outlet. The grinding bead driving device 20 is installed in the grinding cylinder. The rotation direction of the grinding cylinder is opposite to the rotation direction of the rotating shaft 21 in the grinding bead driving device 20. In one embodiment, the pins are only located on the horizontal grinder rotor close to the outlet, and the pins are respectively arranged on a side of the horizontal grinder rotor close to the outlet.
Since the 3D printing time of each horizontal grinder rotor does not exceed twenty-four hours, the cost of the horizontal grinder rotor 10 can be greatly reduced.
A fourth embodiment of a method of making a silicon-carbon composite material is provided. The method of making a silicon-carbon composite material is carried out in the above horizontal grinder. The method comprises following steps: adding grinding beads to the horizontal grinder; adding semiconductor-grade silicon as a silicon source, wherein the size of the semiconductor-grade silicon is greater than ten microns; adding a protective solvent, wherein the protective solvent can be an alcohol such as diethylene glycol or an oil; then grinding the semiconductor-grade silicon to obtain nanoscale silicon particles, wherein the solid content of the nanoscale silicon particles is greater than 15%; then adding carbon sources for homogeneous coating on a surface of the nanoscale silicon particles to obtain the nanoscale silicon-carbon composite material, wherein the carbon sources can be graphite, graphene, carbon black, pitch, carbon nanotubes, etc. Furthermore, a polymer material can be introduced into the carbon sources to increase the viscosity of the carbon sources and make it easy for the carbon sources to coat the nanoscale silicon particles. The polymer material can be polyvinylpyrrolidone (PVP), N-allyl-(2-ethyl xanthate) propionamide (NAPA), dimethylformamide (DMF), or carboxymethyl cellulose (CMC) etc.
Referring to
The method of making a silicon-carbon composite material can realize the self-assembly stacking of silicon-carbon composite materials through grinding, which can improve the electrochemical of the silicon-carbon composite materials. The grinding bead driving device can evenly stir the slurry, increase the frequency of effective collision of grinding beads, and improve the grinding efficiency. While the specific surface area of nano-silicon continues to increase, the grinding bead driving device can still maintain the smoothness of the slurry circulation, and make the silicon particle size reach a set particle size. At the same time, the rotor can be obtained a 3D printing technology. Therefore, the rotor can be used as a consumable for regular replacement, which is beneficial to reduce inventory costs.
The embodiments shown and described above are only examples. Even though numerous characteristics and advantages of the present technology have been set forth in the foregoing description, together with details of the structure and function of the present disclosure, the disclosure is illustrative only, and changes may be made in the detail, including in matters of shape, size and arrangement of the parts within the principles of the present disclosure up to, and including, the full extent established by the broad general meaning of the terms used in the claims.
The above embodiments are only used to illustrate the technical solutions of the present application rather than limitations. Although the present application has been described in detail with reference to the above preferred embodiments, one of ordinary skill in the art should understand that the technical solutions of the present application may be modified or equivalently replaced without departing from the spirit and scope of the technical solutions of the present application.
| Number | Date | Country | Kind |
|---|---|---|---|
| 202210811342.6 | Jul 2022 | CN | national |
