Anode active material for lithium secondary batteries, manufacturing method thereof, and lithium secondary battery comprising the same

Low-irreversibility anode active material pre-doped with silicon nanoparticles via room-temperature reaction in amine-based lithium solution

This technology is a solution-based process that inserts and dopes lithium (or metal) into silicon nanoparticles by mixing them into an amine-based solution in which lithium or metal is dissolved under room temperature and atmospheric pressure conditions.

Conventional silicon-based anode active materials suffer from high initial irreversible capacity due to lithium consumption during the first charge/discharge cycle. Additionally, they face limitations in cycle life as the SEI layer is destroyed by volume expansion and contraction during charging and discharging.

This technology involves dissolving lithium metal or lithium compounds in an amine-based solvent, reacting it with silicon nanoparticles containing a mixture of Si and SiO2, and obtaining pre-lithiated silicon nanoparticles through a two-stage separation process of filtering and residual solvent evaporation. It can be applied to silicon-graphite composite anodes, high-energy EV cells, and pre-lithiation process lines, allowing for full utilization of cathode capacity by compensating for initial efficiency losses without the need for high-temperature or high-pressure equipment.

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Key Features:

• Preparing a lithium solution with dissolved lithium metal or lithium compounds and pulverized silicon nanoparticles
• Preparing a mixed solution by combining the lithium solution with silicon nanoparticles containing a mixture of Si and SiO2 in a molar ratio of 1:0.2 to 5.0
• Primary separation of lithium-silicon nanoparticles from the mixed solution containing residual lithium and solvent via filtering
• Secondary separation and recovery of the lithium-silicon nanoparticles by evaporating the remaining solvent

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This invention was developed with support from the Ministry of Science, ICT and Future Planning for the development of organic environmental pollutant-reducing photoelectrochemical hydrogen production.

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