Graphite spheroidization method and production system thereby

Abstract

The invention discloses a graphite spheroidization method and a production system thereby. The method comprises the following three steps of: (1) ultra-fine pulverizing, namely pulverizing graphite to a proper granularity by utilizing an ultra-fine high-energy pulverizer; (2) reshaping treatment, namely performing reshaping treatment on the pulverized graphite by utilizing a batch-type or continuous reshaping system consisting of one or more special reshaping devices and a micro-nano particle reshaping cladding system; and (3) ultra-fine multilevel classification, namely performing high-precision multilevel series classification on the graphite subjected to reshaping treatment by utilizing an ultra-fin multilevel classification system, so as to obtain narrow granular spherical graphite with the D50 of 3-35mu m. The method and the system haves the following advantages: the product spheroidization effect is good, the tap density is large, the yield of finished products is high, a favorable reshaping effect can be achieved for artificial graphite which is difficult to reshape, the preparation period is short, the processing equipment is compact, and the method is safe and environmentally-friendly.

Description

technical field [0001] The invention relates to a method for spheroidizing natural graphite and artificial graphite materials, in particular to a physical shaping method for spheroidizing artificial graphite and flake graphite materials for negative electrodes of lithium batteries and a related production system. Background technique [0002] Due to its good conductivity, excellent charge-discharge voltage platform, high specific capacity, and wide range of sources, graphite materials have always occupied a dominant position in lithium-ion battery anode materials, and have become a research hotspot in anode materials. Graphite materials for lithium batteries are mainly divided into natural graphite and artificial graphite. Natural graphite is mainly flake graphite, and artificial graphite includes needle coke, petroleum coke, carbon nanotubes and mesocarbon microspheres. Due to the influence of forming conditions and processing technology, the two kinds of graphite have dif...

AI Technical Summary

Problems solved by technology

Due to the influence of forming conditions and processing technology, the two kinds of graphite have different material structures, resulting in large differences in material properties.

Compared with artificial graphite, natural graphite has large specific capacity, simple process, and relatively low price, but has poor stability, poor rate performance, and poor electrolyte adaptability

In order to improve the cycle stability and tap density of graphite, natural graphite is made into spherical or nearly spherical in industry, but due to the limitation of its preparation process, the product yield is low, energy consumption is large, and the cost is high, and the spherical shape is obtained. The sphericity of graphite is not high, and the performance of the product is not ideal

Artificial graphite (except for mesophase carbon microspheres) is prone to volume crushing during the spheroidization process due to its high hardness, and it is difficult to make it into a spherical shape with existing equipment and processes

[0003] At present, the domestic graphite spheroidization equipment is mainly eddy current mill, there is no professional shaping equipment, and the shaping mechanism is mostly impact shaping. If the impact force is too large, the graphite particles will be broken, resulting in a decrease in yield. Artificial graphite The equipment has poor shaping effect and can only be crushed

Although there are other equipment for shaping graphite in foreign countries, they are expensive, and the shaping effect on artificial graphite is still not good.