Lithium Titanium Oxide-Based Anode Active Material, Manufacturing Method Thereof, and Lithium Secondary Battery Using the Same

High-Rate LTO Composite Anode Material with Li2Ti3O7 Phase Formed via Nitrogen Partial Pressure-Controlled Pyrolysis

This technology produces an LTO/Li2Ti3O7 composite anode active material with controlled oxygen vacancy concentration by heat-treating Li4Ti5O12 (LTO) in a nitrogen-containing reactive gas atmosphere to partially decompose it into Li2Ti3O7.

Conventional LTO materials suffer from poor rate capability due to low electronic conductivity and a sharp capacity drop at the end of charge/discharge cycles. Previous attempts to improve this through nanostructuring or carbon coating have been limited by particle agglomeration and process complexity.

This technology uses a tube furnace to control nitrogen partial pressure, selectively decomposing LTO and regulating the Li2Ti3O7 content. This facilitates charge transfer on the active material surface, improving rate capability and structural stability to achieve a Peukert constant of 1.26 or less. Applicable to hybrid vehicle batteries for regenerative braking, high-power electric tool cells, and frequency regulation ESS, it boosts capacity retention at high discharge rates simply by adjusting gas type and flow.

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Key Features:

• Preparing a base precursor by mixing lithium carbonate (Li2CO3) and titanium dioxide (TiO2) as lithium and titanium sources
• Sequentially supplying a first reactive gas with low nitrogen partial pressure followed by a second reactive gas with high nitrogen partial pressure
• Heat-treating the base source in a tube furnace to produce an active material containing Li4Ti5O12 and Li2Ti3O7
• Controlling the phase fraction by increasing the Li2Ti3O7 ratio in the active material through adjustments to reactive gas type and flow rate

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This invention was developed with support from the Ministry of Science and ICT for the discovery and investigation of new photoelectrochemical phenomena: controlling photoelectrochemical behavior through interface engineering.

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