A kind of preparation method of lithium battery modified silicon-based negative electrode material

Abstract

The invention belongs to the technical field of lithium ion battery negative electrodes, and specifically relates to a preparation method of a lithium battery modified silicon-based negative electrodematerial. The preparation method of the lithium battery modified silicon-based negative electrode material comprises the steps of (1) dissolving magnesium nitrate, aluminum nitrate, sodium silicate and sodium lauryl sulfate in distilled water, adding citric acid to adjust the pH value to 4, adding an acrylonitrile monomer and an initiator, and dropwise adding a mixed solution of sodium hydroxideand sodium silicate to obtain organic phase closely-compounded hydrotalcite; and (2) blending and pressing the organic phase closely-compounded hydrotalcite and graphene into a sheet, forming a carbonfiber with a graphite phase after pre-oxidation and high-temperature carbonization, spraying a layer of magnesium powder on the surface of the sheet, carrying out heating treatment for 30 minutes, and then cooling and washing to obtain the required negative electrode material. The negative electrode material prepared by the invention has a relatively wide interlayer spacing, and nano silicon witha relatively large specific surface area is embedded between graphite-phase carbon layers, so that the endurance capacity and the charging and discharging speed of the negative electrode under a fastcharging condition are improved.

Description

technical field

[0001] The invention belongs to the technical field of negative poles of lithium ion batteries, and in particular relates to a preparation method of modified silicon-based negative pole materials for lithium batteries. Background technique

[0002] Lithium-ion battery is a high-energy secondary battery that mainly relies on the movement of lithium ions between the positive and negative electrodes to work. With the rapid development of electronic portable devices and electric vehicles, it is particularly critical to research and develop high-performance lithium-ion batteries. Lithium-ion batteries are mainly composed of four parts: positive electrode materials, negative electrode materials, separators, and electrolytes. Among them, positive electrode materials are the key to determining battery performance and cost in commercial lithium-ion batteries. At present, the mainstream anode materials are carbon-based and silicon-based. The silicon anode for lithium-...