Technology for processing cladded superfine graphite powder

Abstract

The invention relates to a processing technology for preparing cladded superfine graphite powder for composite graphite cathode materials of multiple types of secondary batteries in a high-temperature semiliquid spraying manner. The technology comprises the following steps: firstly, putting 60-90% of powdered graphite into a high-temperature reaction kettle protected by an inert gas at 300-500 DEG C; heating 10-40% of nanoscale mesophase pitch for a cladding layer to the semiliquid state and then spraying nanoscale droplets into the high-temperature reaction kettle at a high speed by a nano nozzle, mixing and cladding the powdered graphite for 2-3 hours to form cladded graphite; then drying the cladded graphite in hot air at 200 DEG C for 2-3 hours; carrying out carbonizing treatment at 700-1200 DEG C and graphitizing treatment at 1,000-3,000 DEG C, so as to obtain the balanced cladded superfine graphite powder. The prepared product is good in cladding uniformity and sphere integrity, low in irreversible capacity for the first time, high in circulating stability, low in charge and discharge voltage, and long in circulating service life, and can be widely applied to cathode materials of multiple typs of secondary batteries.

Description

Technical field: [0001] The invention relates to a preparation method for composite graphite negative electrode materials used in various secondary batteries, in particular to a processing technology for coating ultrafine graphite powder. technical background: [0002] Secondary batteries are a new generation of batteries since the 1990s after nickel-metal hydride batteries, represented by lithium-ion batteries, because of their high operating voltage, high energy density, long cycle life, small self-discharge, and no memory. Effect and other advantages, it has become the preferred chemical power source for high-end electronic consumer products, and has penetrated into aerospace, military and other cutting-edge technology fields. Accompanied by its increasing demand, secondary batteries are becoming the focus and focus of scientific and technological research and development in the new century. Natural graphite is widely used in the manufacture of secondary batteries becaus...

AI Technical Summary

Problems solved by technology

The prior art method has the disadvantages of environmental pollution, graphite particles after coating are easy to bond, and the coating layer is likely to be peeled off and damaged in the subsequent crushing process, which affects the overall performance of the negative electrode material.

Moreover, in the existing coating method, the coating molecules are too large and the graphite powder below 15um often cannot be formed into a spherical shape, resulting in uneven coating.