Preparation method and application of high-safety biomass silicon synthesized SiOx@C material

Abstract

The invention provides a preparation method of a high-safety biomass silicon synthesized SiOx@C material. The method comprises the following steps: pickling rice hull ash, carbonizing a proper amountof the rice hull ash in an inert atmosphere, uniformly mixing and ball-milling the carbonized product, metal powder and molten salt, putting the mixture into a furnace, introducing inert gas, carryingout a high-temperature reaction, and pickling to clean byproducts to obtain the product of the SiOx@C material. The method is simple and feasible in process, rich and cheap in raw materials and higher in safety compared with magnesiothermic reduction, and the obtained SiOx@C particles have porous structures, are uniform in carbon coating and good in rate capability and can be applied to the fieldof lithium battery negative electrode materials.

Description

technical field [0001] The invention belongs to the technical field of preparation of new energy materials, in particular to a high-safety biomass silicon synthesis SiO x Preparation method of @C material. Background technique [0002] Improving the specific energy of power batteries is the most effective way to solve the "range anxiety" of electric vehicles at this stage. According to authoritative data, lithium-ion power batteries must reach the development goal of 300 W h / kg by 2020. At present, the only feasible technical route is: high-nickel ternary positive electrode material NCM 811, NCA or lithium-rich manganese base with silicon-based negative electrode Material. [0003] Studies have shown that for every 500 mA h / g increase in the specific capacity of the negative electrode material, the specific energy of the lithium-ion battery can be increased by 15%. The theoretical specific capacity of silicon-based negative electrode materials can reach up to 4200 mA h / g,...

AI Technical Summary

Problems solved by technology

As described in the CN 201810059105.2 patent, the synthesis conditions of this method are harsh, the requirements for equipment are too high, and it is difficult for large-scale industrial production

In addition, the method of obtaining elemental silicon by magnesium thermal reduction of biomass is also widely used, as described in the patent CN 201811476229 .7, but since magnesium powder is a flammable and explosive controlled drug, only a small amount of experiments can be carried out, and it is not suitable for large-scale production

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