Novel V-O Based Electrode Material for Lithium Batteries

Orthorhombic Vanadium Oxide Cathode Material Based on Precursor Particle Size Control and Vacuum-Sealed Heat Treatment

This technology synthesizes orthorhombic V4O9 with a Cmcm space group and specific lattice parameters for use as a lithium secondary battery cathode active material, enhancing electrochemical performance by controlling the particle size of the V2O5 precursor.

Conventional V4O9 vanadium oxide has primarily been studied in thin-film form, making it difficult to accurately evaluate its capacity and performance as a bulk material. Furthermore, there was a need to improve energy density and power characteristics compared to commercial LiCoO2 cathode materials.

This technology involves reacting oxalic acid with V2O5 to control the precursor particle size, mixing it with sulfur (S) as a reducing agent, and performing heat treatment at 350–450°C in a vacuum-sealed environment to synthesize orthorhombic V4O9 with lattice constants of a=8.50–12.5Å, b=7.10–9.3Å, and c=14.5–18.6Å. Applicable to lithium secondary battery cathodes aiming to reduce cobalt usage and the development of vanadium-based alternative cathode materials, it enables the production of powder-type cathode materials with reversible charge/discharge capacity while reducing dependence on rare metals.

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Key Features:

• A step of synthesizing particle-size-controlled V2O5 by stirring oxalic acid and V2O5 in distilled water at a 1:6 molar ratio, followed by heat treatment at 350 to 450°C.
• A step of pulverizing the particle-size-controlled V2O5 and S separately, then mixing them to obtain a mixture.
• A step of placing the pulverized mixture of V2O5 and S into a silica tube and sealing it in a vacuum atmosphere.
• A step of heating the sealed silica tube in an oven from 350°C to 450°C over 5 to 7 hours, followed by heat treatment for 10 to 14 hours.

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