Cathode Active Material for Lithium Secondary Batteries and Manufacturing Method Thereof

High-Efficiency LiMnO2-Based Cathode Material Using Trace Vanadium Doping and Continuous Two-Stage Calcination

This technology enhances the structural stability of LiMnO2-based cathode active materials by doping them with vanadium (V) at a molar ratio of 1:0.01–0.02 relative to manganese. It also utilizes a two-stage heat treatment process to suppress impurity formation, thereby improving charge-discharge efficiency and capacity.

Conventional LiMnO2-based cathode active materials have suffered from low capacity and degradation during repeated charge-discharge cycles. Furthermore, excessive doping often led to the formation of impurities such as Li3VO4, which hindered performance.

This technology precisely controls the vanadium-to-manganese molar ratio at 0.01–0.02 within the Li1+a(Mn1-bMb)1-aO2 (M=V) composition. By performing continuous heat treatment—a first stage at 400–600°C and a second stage at 450–750°C in an oxygen atmosphere—it increases crystallinity and minimizes impurity formation. Applicable to entry-level electric bicycle batteries aiming to reduce cobalt usage or to high-capacity manganese-based ESS cells, this technology paves the way for producing cathodes with reduced charge-discharge efficiency loss, even when using cost-effective manganese raw materials.

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Key Features:

• Cathode active material comprising a compound represented by the chemical formula Li1+a(Mn1-bMb)1-aO2, where a is between 0 and 1/3, and M is vanadium.
• Compound containing vanadium at a molar ratio of 1:0.01–0.02 relative to manganese to suppress the formation of impurities such as Li3VO4.
• First heat treatment stage involving heating a mixture of lithium, manganese, and vanadium sources at 400°C–600°C for 10–20 hours.
• Second heat treatment stage involving continuous heating of the first-treated mixture at 450°C–750°C for 10–20 hours.

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