Li-ion secondary battery cathode material preparation method with nuclear shell structure

Abstract

The invention relates to a Li-ion secondary battery cathode material preparation method with a nuclear shell structure; the preparation method is characterized in that: SiO, asphalt and graphite are weighted and are added in solvent for carrying out stirring; drying is carried out; the solvent is extracted out to obtain precursors which are uniformly distributed; the precursors are arranged in a high-temperature furnace, high-temperature sintering is carried out at inert atmosphere, the temperature is reduced to room temperature, so as to obtain the Li-ion secondary battery cathode material preparation method with the nuclear shell structure; meanwhile, the SiO, the asphalt and the graphite are chosen as initial raw material, so as to prepare the Si-SiO2-C electrode material with the nuclear shell structure, when the volume of the buffering Si material is expanded, the electricity-conducting capacity of the electrode material is ensured and the electro-chemical Li-embedded reaction property of the electrode material is improved; the asphalt is used as a carbon source, while reducing the product cost, the material is coated; a regular carbon layer structure is set up in the material body and on the surface, so as to improve the electricity-conducting performance of the material; the method has simple process and is suitable for large-scale industrial production.

Description

technical field [0001] The invention belongs to the technical field of lithium-ion battery materials, in particular to a method for preparing a lithium-ion secondary battery negative electrode material with a core-shell structure. Background technique [0002] Since 1990, Japan's Sony (Sony) took the lead in using flaky graphite anodes to replace the extremely unsafe metal Li, and launched the first practical rocking chair battery, the application range of lithium-ion batteries has continued to expand, from mobile Communication power supplies, notebook computers, cameras, etc. have expanded to power tools, electric vehicles and other fields. However, the theoretical capacity of the currently widely used carbon anode material is only 372mAh / g, which cannot meet the needs of the development of higher specific energy lithium-ion batteries. Finding negative electrode materials with lithium storage capacity has always been a research hotspot in the field of lithium-ion batteries...

AI Technical Summary

Problems solved by technology

However, during the electrochemical lithium intercalation process of Si, a complex phase transition occurs accompanied by a huge volume change, which will inevitably lead to the pulverization of Si and Si-based electrodes, which will reduce the utilization rate of electrode active materials, which has become a commercial product for Si electrodes. An important bottleneck of the application