Method for preparing silicon-carbon nano hybrid material by wrapping silicon particles with chloroprene rubber adhesive and lithium ion battery negative electrode

Abstract

The invention discloses a method for preparing a silicon-carbon hybrid negative electrode material of a lithium ion battery through a simple process by taking Si nanoparticles and chloroprene rubber as raw materials, and belongs to the technical field of lithium batteries. The silicon-carbon composite material prepared by the invention has an obvious core-shell structure, the core is nano silicon, the middle layer of the shell is SiO2, and the outer layer of the shell is a porous carbon material. The specific synthesis process comprises the following steps: dispersing Si nanoparticles in a beaker containing 30 ml of deionized water, and ultrasonically stirring for 30 minutes to obtain a solution A; adding the chloroprene rubber emulsion into the solution A according to the mass ratio of Si to chloroprene rubber of 1: 3, and fully stirring for 30 minutes to obtain a solution B; an ethanol solution is rapidly added into the solution B, chloroprene rubber is rapidly separated out in ethanol, Si nano-particles are wrapped, and a Si and chloroprene rubber structure is formed. And calcining the Si-coated chloroprene rubber in a tubular furnace, partially oxidizing the surfaces of the Si nanoparticles to form a Si-coated SiO2 structure, and continuously heating to generate a target product Si-coated SiO2-coated C3 as the lithium battery negative electrode.

Description

technical field [0001] The invention belongs to the field of electrochemical application of functional nano-composite materials, more specifically, a method for preparing silicon-carbon hybrid negative electrode materials based on silicon nanoparticles and polymer materials and its application in lithium-ion batteries. [0002] technical background [0003] In order to meet the increasing demands of portable electronic devices, high capacity and long service life of Li-ion batteries have become an urgent need. Graphite is currently the most widely used anode material in commercial lithium-ion batteries. However, the slow intercalation kinetics and low theoretical specific capacity (372mAh / g) of industrial graphite limit the rate capability of lithium-ion batteries. As an alternative material, Si due to its appropriate delithiation potential (0.4 V vs Li / Li + ) and high theoretical capacity of 4200 mAh / g have attracted widespread attention. However, the huge volume change (&...

AI Technical Summary

Problems solved by technology

Although a series of preparation methods of silicon-carbon hybrid materials have been reported in recent years, so far, the one-step synthesis of silicon-carbon hybrid materials and the simultaneous introduction of oxygen have not been reported.

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