Method for Synthesizing Silicon Composites Containing Nano-Silicon for Lithium Secondary Battery Anodes Using Metal Compounds, Anode, and Lithium Secondary Battery Including the Same

Manufacturing Method for Anode Materials Synthesizing Nano-Silicon via Low-Temperature Heat Treatment of Metal Compounds

This technology involves mixing a silicon oxide (SiO) precursor with metal compounds (such as Li or Na compounds) and heat-treating the mixture. This process forms a composite containing nano-silicon (crystalline Si) and crystalline metal silicate (Me_ySi_zO) at low temperatures, eliminating the need for conventional high-temperature processes.

Silicon anode materials suffer from electrode degradation and shortened lifespans due to rapid volume expansion during lithium insertion and extraction. Furthermore, existing methods for forming nano-silicon involve high manufacturing costs and complex processes, such as pulverization, due to the requirement for high-temperature heat treatment.

By mixing SiO with metal compounds (e.g., lithium hydroxide) using a ball mill and heating the mixture in an inert atmosphere at 500–1000°C, this technology produces a composite where nano-silicon is dispersed within a crystalline metal silicate matrix that mitigates volume expansion. This improves anode lifespan and offers a practical solution for developing next-generation secondary battery anode materials.

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Key Features:

• Preparing a precursor mixture containing silicon oxide and metal compounds for nano-silicon synthesis
• Heating the precursor mixture to synthesize a composite containing crystalline silicon, amorphous silicon oxide, and crystalline metal silicate
• Synthesizing the silicon composite using alkali metal or alkaline earth metal compounds as the metal compound
• Manufacturing anode materials that form nano-silicon and crystalline metal silicate at low temperatures without high-temperature processing

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