Preparation method and preparation apparatus of spherical graphite for power battery

Abstract

The invention provides a preparation method and a preparation apparatus of spherical graphite for a power battery, wherein a combined process including ultrafine initial pulverization, ultrafine finepulverization and multi-time ultrafine classification is employed, so that the prepared spherical graphite has good degree of sphericity, narrow granularity distribution (D50 = 3-12 [mu]m) and high tap density, which satisfy the use requirement of negative electrode materials for high-grade power batteries. In addition, since a tailing generated from a preparation process of the spherical graphitewith D50 being 13-25 [mu]m can be used as the raw material for producing the small-diameter spherical graphite (D50 = 3-12 [mu]m), the utilization rate on the graphite raw material can be further improved by 25-35%. The method is simple in process and reduces energy resource consumption. The preparation apparatus includes a plurality groups of head-to-tail connected single devices, wherein raw material, after first-stage pulverization, is directly fed into the nest stage for circulating pulverization and classification; the raw materials are conveyed by pipelines. The whole set of apparatus is sealed, so that dust-containing gas is subjected to dust removal and is fed into a blind drain for secondary dust removal treatment after collection, thus achieving zero-pollution emission.

Description

technical field [0001] The invention belongs to the technical field of graphite preparation, and relates to a method and device for preparing spherical graphite for power batteries, in particular to a median particle diameter D 50 A method and device for preparing spherical graphite with a thickness of 3-12 μm. Background technique [0002] Lithium-ion batteries have become a new generation of secondary batteries since the 1990s after nickel-metal hydride batteries because of their advantages such as high operating voltage, high energy density, long cycle life, small self-discharge, and no memory effect. At present, the anode materials of commercial lithium-ion batteries are still dominated by graphite materials, among which natural graphite is widely used because of its high charge and discharge capacity, good charge and discharge platform, wide range of sources, and low cost. [0003] In recent years, with the continuous improvement of the miniaturization, light weight, m...

AI Technical Summary

Problems solved by technology

At present, the traditional spherical graphite preparation process adopts a jet mill to undergo multiple coarse crushing, fine crushing, spheroidizing, grading and screening processes to obtain a spherical graphite with a median particle size (D 50 ) minimum is 14μm, it is difficult to further reduce the median particle size of spherical graphite, which cannot meet the requirements of high-end power batteries

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