Method for preparing lithium ion battery silicon-carbon anode material by using carbon nanotube

Abstract

The invention discloses a method for preparing a lithium ion battery silicon-carbon anode material by using a carbon nanotube. The method of the invention comprises dispersing and fixing the carbon nanotube and carbonizing a precursor. The method shortens and disperses the carbon nanotube by high-speed emulsification shearing. A dispersing agent keeps the carbon nanotube in a highly dispersed state, thereby solving the problem that the carbon nanotube is difficult to disperse and easy to agglomerate. By freeze drying, an organic carbon source fixes the highly dispersed carbon nanotube/nanosilicon. The carbon nanotube/nanosilicon is coated with carbon after the carbonization by the organic carbon source so as to achieve a purpose of efficiently preparing the lithium ion electronic silicon-carbon anode material from the carbon nanotube. The method of the invention is environmentally friendly and reproducible, is simple and easy, and low in equipment requirement and low in energy consumption, and can achieve large-scale production.

Description

technical field [0001] The invention belongs to the technical field of negative electrode materials for lithium ion batteries, in particular to a method for preparing silicon carbon negative electrode materials for lithium ion batteries by using carbon nanotubes. Background technique [0002] In order to meet the increasing demand for lithium-ion battery capacity and energy density in new energy vehicles and portable devices, carbon-silicon anode materials have become one of the leading development directions for lithium-ion battery anode materials in the future. The development of carbon-silicon anode materials is based on the use of silicon's ultra-high theoretical capacity and low lithium intercalation potential, and silicon is rich in resources and environmentally friendly. However, the shortcomings of the silicon material itself are also extremely significant, such as poor electrical conductivity, poor cycle performance, and high expansion rate; current research general...

AI Technical Summary

Problems solved by technology

However, the shortcomings of the silicon material itself are also extremely significant, such as poor electrical conductivity, poor cycle performance, and high expansion rate; current research generally uses the carbon-silicon composite method to avoid disadvantages, but the uniformity of silicon-carbon composites, capacity The problems of fast attenuation, poor rate performance, and complicated preparation methods have not yet been overcome

[0003] Carbon nanotubes can effectively solve the above problems; carbon nanotubes are a one-dimensional nanomaterial with a radial dimension of the order of nanometers and an axial dimension of the order of micrometers. An excellent conductor of ions and electrons. Lithium ions and electrons reach silicon particles through carbon tubes for intercalation and detachment, which maximizes the advantages of silicon; however, carbon nanotubes are prone to agglomeration and entanglement. Excellent performance, how to uniformly disperse and immobilize carbon nanotubes in silicon carbon anode materials is a key problem to solve its efficient application

Images