Aqueous slurry composition for cathodes, and cathodes and lithium secondary batteries manufactured therefrom

Aqueous slurry for high-nickel cathodes with side-reaction suppression using kosmotropic anion-based aqueous electrolytes

This technology introduces a kosmotropic anion-containing aqueous electrolyte into the slurry composition to reduce the activity of water molecules, thereby suppressing side reactions between the cathode active material and water molecules during aqueous processing.

Aqueous processing typically triggers side reactions between water and cathode active materials—particularly high-nickel materials—leading to instability and increased pH. This often results in current collector corrosion, which degrades battery performance and cycle life.

This technology ensures interfacial stability in aqueous slurries by adding metal salts—composed of kosmotropic anions such as SO4^2-, TFA-, Cl-, BF4-, and PO4^3-, and cations such as Li+, Na+, and Mg^2+—at a concentration of 0.1 to 2.0 M. It is ideal for eco-friendly cathode coating lines aiming to eliminate NMP organic solvents or for transitioning high-nickel cathodes to aqueous processes, effectively reducing both solvent recovery costs and VOC emissions.

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Key Features:

• Metal salts containing kosmotropic anions selected from SO42-, TFA-, Cl-, BF4-, and (PO4)3- and cations such as Li+ and Na+
• Aqueous electrolyte containing the metal salt at 0.1 to 2.0 M with water, mixed with the cathode active material and aqueous polymer
• Cathode active material dispersed in the aqueous electrolyte, comprising 40 to 60 wt% of the total slurry composition
• Aqueous polymer, such as cellulose, polyacrylic acid, or styrene-butadiene rubber, included in a weight ratio of 1:0.01 to 0.1 relative to the aqueous electrolyte

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This invention was developed with support from the Ministry of Science and ICT for the Single-Ion Conductor-Based Multidimensional Free-Form Power System project.

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