Transition metal compound, method for manufacturing the same, and electrode active material for lithium secondary batteries comprising the same

Titanium-cobalt oxide electrode active material with expanded internal pores via sequential nitridation and oxidation

This technology involves heat-treating bulk transition metal oxides in a nitrogen atmosphere to replace some oxygen with nitrogen and create pores, followed by additional heat treatment in an oxygen atmosphere to produce nitrogen-doped porous transition metal compounds.

Conventional bulk transition metal oxides have small specific surface areas and large grain sizes, which limit lithium-ion diffusion rates and result in poor capacity and cycle life when used as electrode active materials in lithium secondary batteries.

This technology nitrides TiO2 or Co3O4 bulk oxides in an ammonia atmosphere to create titanium oxynitride or cobalt monoxide intermediates, then oxidizes them in an oxygen atmosphere. This transforms them into a nanoporous structure with smaller grains and introduced pores while maintaining the original crystal structure. Applicable to high-capacity anode active materials for mobile devices and power tool batteries, it maintains the original composition while expanding internal pore area beyond the external surface area, significantly increasing electrolyte contact.

‍

‍

Key Features:

• Nitridation of titanium-containing transition metal oxide in a nitrogen-containing gas atmosphere to produce a titanium oxynitride intermediate
• Oxidation of the intermediate in an oxygen-containing gas atmosphere after nitridation to produce nitrogen-doped titanium oxide
• A transition metal compound with smaller grains than the transition metal oxide while maintaining the same crystal structure
• Cobalt oxide with an internal pore area larger than its external surface area, achieved through sequential nitridation and oxidation

‍

This invention was developed with support from the Samsung Science and Technology Foundation for research on developing high-capacity/fast-charging electrode materials using sequential gas-phase reactions.

‍