PREPARATION METHOD FOR HIGH CAPACITY LITHIUM-ION BATTERY NEGATIVE ELECTRODE MATERIAL

摘要

A preparation method for a high capacity lithium-ion battery negative electrode material: natural flake graphite serving as a raw material, concentrated sulfuric acid serving as an intercalation agent, and potassium permanganate serving as an oxidizing agent are expanded at a high temperature to produce micro-expanded graphite, then the micro-expanded graphite of different proportions is mixed with tin nanopowder, ultrasound dispersed, suction filtered, and dried to produce micro-expanded graphite having tin nanopowder inserted between layers that is mixed and cladded with a carbon source precursor according to a certain ratio, and then carbonized and sintered under the protection of a noble gas, thus preparing a tin-carbon composite negative electrode material that is completely cladded and provided therein with sufficient reserved expansion space. It is shown electrochemically that the tin-carbon composite material prepared per the present method is provided with increased specific capacity and cycle stability and is an ideal high capacity lithium-ion battery negative electrode material.