Boron-doped silicon oxide-based anode active material, manufacturing method thereof, and lithium secondary battery using the same

Silicon oxide anode material boron-doped without impurities via vapor-phase diffusion from a dummy substrate

This technology is a doping process that selectively diffuses only boron elements into silicon oxide by placing a dummy substrate coated with a boron compound dopant at a physical distance from silicon oxide powder and performing heat treatment, thereby leaving no boron compound impurities behind.

Silicon oxide-based active materials have historically suffered from low electrical conductivity and poor long-term cycle life. Conventional methods of directly mixing dopants with active materials often leave residual boron compound impurities, which limit the specific capacity of the active material.

By placing a substrate coated with a boron compound, such as borosilicate, at a distance from the silicon oxide powder and heat-treating them at 800–1000°C, this technology enables uniform doping of only boron elements via vapor-phase diffusion, while also inducing silicon crystallization. It can be applied to mass production lines for silicon-based anode materials for electric vehicles and high-capacity IT devices, allowing for the production of anode materials with improved ion diffusion rates and cycle characteristics without the need for a post-doping cleaning process.

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Key Features:

• Coating a boron-containing dopant onto a dummy substrate using spin coating, drop coating, or spray aerosol methods
• Placing the dopant-coated dummy substrate and the silicon oxide-based mixture at a distance from each other, followed by heat treatment at 800 to 1000°C
• At least one boron compound selected from the group consisting of borosilicate, boron trioxide, boron oxide, boron suboxide, and boric acid
• Coating a metal current collector with a slurry made by mixing the boron-doped anode active material with conductive agents and binders, followed by heat treatment

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