5V-class spinel cathode active material and method for manufacturing the same

High-Voltage Spinel Cathode Material with Controlled Mn Oxidation State via High-Valence Transition Metal and Halogen Co-Doping

This technology improves structural stability and cycle life in 5V-class spinel cathode active materials (LiNixMny-αM1αO4-βM2β) by co-doping with high-valence metals (M1) such as Nb, Mo, Ta, and W, and anions (M2) such as F and Cl, precisely controlling the average Mn oxidation state between 3.5 and 4.

Conventional spinel cathode materials (LiMn2O4) suffer from structural collapse due to manganese dissolution during high-voltage charge/discharge cycles, resulting in low discharge capacity. Furthermore, they face rapid performance degradation as the number of charge/discharge cycles increases.

This technology stabilizes the crystal structure and suppresses surface degradation by doping the precursor with +5 or +6 valence transition metals (M1) during wet co-precipitation, followed by dry ball-milling to dope with anions (M2), adjusting the Mn3+ content to a range of 0.3% to 3.38%. It can be applied to cobalt-free high-voltage EV batteries, high-power power tools, and hybrid vehicle cells, reducing reliance on rare metals while ensuring durability in the 5V operating range.

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Key Features:

• 5V-class spinel cathode active material represented by LiNixMny-αM1αO4-βM2β with an average Mn oxidation state between 3.5 and 4
• M1 doping transition metal with a +5 or +6 oxidation state, including at least one of Nb, Mo, Ta, and W
• Step of preparing an M1-doped cathode active material precursor by supplying nickel and manganese transition metal aqueous solutions, an M1 doping metal aqueous solution, and an ammonia solution to a reactor
• Step of dry-mixing the cathode active material precursor, lithium salt, and a doping source containing F or Cl via ball-milling, followed by calcination

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This invention was developed with support from the Ministry of Science and ICT for the development of core and commercialization technologies for interface-optimized, rod-shaped secondary battery materials.

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