Preparation method of nanometer SiC capable of being used as negative electrode material of lithium ion battery

Abstract

The invention discloses a preparation method of nanometer SiC capable of being used as a negative electrode material of a lithium ion battery, belonging to the technical field of lithium ion batteries. The preparation method of the nanometer SiC comprises the following steps: mixing SiO2, graphite, isopropanol, polyvinyl alcohol and polyethylene glycol, carrying out drying and sintering successively to obtain a SiO2 / graphite mixture, and carrying out electrodeoxygenation by using molten CaCl2 to synthesize the nanometer SiC material. The nanometer SiC material has a unique nanowire form and uniform element distribution, shows stable charge-discharge properties, has specific capacity and volume capacity higher than the specific capacity and volume capacity of a graphite material and can become the negative electrode material with potential competitiveness for the lithium ion battery; the effects of simple preparation process flow, relatively low cost and relatively low energy consumption can be realized; high-selectivity large-scale production can be realized by controlling process conditions; and the problems of high production temperature, high impurity content of a product, difficulty in batch production and the like when SiC is prepared by a conventional carbothermic reduction method are solved.

Description

technical field [0001] The present invention relates to the technical field of lithium ion batteries, more specifically, relate to a kind of preparation method that can be used as the nanometer SiC of lithium ion battery anode material. Background technique [0002] Lithium-ion batteries dominate the power supply market for portable electronic devices due to their good overall performance (including high operating voltage, high energy density, low self-discharge, and design flexibility). As one of the essential components of lithium-ion batteries, the anode active material must have the ability to conduct ions and electrons, and be able to accommodate a large amount of Li in the structure in a reversible manner. Because the chemical activity of Li embedded in it is only slightly lower than that of Li in the single state, and the volume change is relatively small during the charge-discharge cycle, graphite materials have been the most widely used mainstream anode materials. ...

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Problems solved by technology

[0004] However, the methods mentioned above, as well as preparation methods such as physical and chemical vapor deposition, sol-gel method, etc., have not been able to achieve large-scale commercial application due to the complexity of the synthetic route and high cost.

At present, the main commercial production method of SiC is the carbothermal reduction method. In this method, quartz sand and coke need to undergo a reduction reaction above 2500°C to form SiC. A few percent, the lack of purity is obvious, it is difficult to generate high value-added nano-SiC powder

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