A silicon nanowire, its preparation method and its application for preparing carbon-coated silicon nanowire anode material

Abstract

The invention discloses a silicon nanowire, a preparation method thereof and an application for preparing a carbon coated silicon nanowire anode material. The method for preparing the silicon nanowire comprises the steps of compacting mixed powder of silicon dioxide and sodium chloride into a cathode slice; carrying out low temperature sintering on the cathode slice; fixing the obtained cathode slice on a iron chrome alloy silk as a cathode, taking high purity graphite as an anode, and carrying out electrolysis in a molten salt system of CaCl <2 > under a high purity argon atmosphere, thereby obtaining the silicon nanowire; carrying out ball milling on enough acetylene black and the silicon nanowire; and sintering the powder obtained through ball milling in an inert atmosphere, thereby obtaining the carbon coated silicon nanowire anode material. The silicon nanowire provided by the invention is good in shape, the carbon coated silicon nanowire anode material is prepared by taking the silicon nanowire as a precursor, and the material is assembled into the cell; the cell has very good cell circulation performance, the electrochemical performance is stable, and the energy density is high; and the preparation method provided by the invention is simple, the production cost is low, and the raw material utilization ratio is high.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion and sodium-ion batteries, and relates to a silicon nanowire, its preparation method and application, in particular to a silicon nanowire, its preparation method and its application for preparing a carbon-coated silicon nanowire negative electrode material . Background technique [0002] Compared with traditional graphite anode materials, silicon has a very high mass specific capacity of 4200mAh / g, which is more than ten times that of natural graphite; compared with metal lithium, because the packing density of silicon in alloy materials is similar to that of lithium, silicon It also has a high volume specific capacity; unlike graphite materials, the high specific capacity of silicon comes from the alloying process of silicon lithium, so the silicon negative electrode material will not co-intercalate with the electrolyte, and the scope of application of the electrolyte Wider; Compared with car...

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Problems solved by technology

However, the electrolysis temperature of this patent is at a relatively high temperature of 650°C to 1010°C, which consumes a lot of energy and is not conducive to energy-saving production.

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