A preparation method of silicon oxide-based negative electrode material for lithium ion battery

Abstract

The invention discloses a method for preparing a silicon monoxide-based anode material for a lithium ion battery, and belongs to the fields of new materials and electrochemistry. The method comprisesusing organic silicon as a silicon source and organic carbon as a carbon source; obtaining a silica / carbon precursor by a sol-gel method; and preparinga SiOx / C composite material having double interfaces by a carbon thermal reduction reaction occurring during a high-temperature heat treatment process. The method controls the colloidalization process of the organic silicon source to uniformly disperse the silicon source and the carbon source, enhances the ability of the carbon thermal reduction reaction in the heat treatment process, and obtains the silicon monoxide-based anode material with agood pyrolytic carbon coating effect. In addition, by adding a loosening agent, the method solves problem that the material is easily densified during the heat treatment. The anode material has high specific capacity and good cycle stability. The method is easy to operate and low in cost. The preparation process does not relate to acid washing and centrifugation. The method has a good applicationprospect.

Description

Technical field[0001]The invention belongs to the field of new materials and electrochemistry, and specifically relates to a lithium ion battery silicon oxide-based negative electrode material and a preparation method thereof.Background technique[0002]As a new generation of green secondary batteries, lithium-ion batteries have the advantages of high energy density, high rated working voltage, low self-discharge rate, good cycle performance, and high charge and discharge efficiency. They are widely used in portable electronic equipment, electric vehicles and energy storage fields. . However, due to the specific capacity of conventional positive and negative active materials, it is difficult for the current commercial lithium-ion batteries to meet the demand for higher energy density. Therefore, the development of high-energy density electrode materials is an important application research direction of lithium-ion batteries.[0003]Graphite is currently the most commonly used negative e...

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Problems solved by technology

However, the reaction time is too long, the stirring time for hydrolysis of ethyl orthosilicate needs 24 hours, and the hydrothermal time in the reactor needs 48 hours, and the preparation is too long and complicated, which is not conducive to industrialization

[0006] CN 103700816A patent mixes silicon oxide, silicon and graphite ball mills and then mixes them with asphalt, and then heats them at high temperature to obtain silicon-silicon oxide-carbon composite negative electrode materials for lithium-ion batteries. Graphite and pyrolytic carbon alleviate the volume Swells and provides a conductive network, but capacity drops faster during cycling due to poor coating

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