Cathode electrode for lithium secondary batteries comprising a bilayer cathode active material

High-Capacity, Long-Life Bilayer Cathode with NCM Base Layer and Thick LCO Top Layer

This technology features a bilayer structure with a high-capacity NCM (Li(NixCoyMnz)O2) layer on the current collector and a highly stable LCO (LiCoO2) layer on top, simultaneously achieving high capacity and structural stability.

Using a single material presents trade-offs: NCM offers high capacity but short lifespan, while LCO provides high safety but low capacity. Furthermore, conventional electrodes suffer from rapid degradation and cracking of active materials far from the current collector during repeated cycling, limiting efficiency and lifespan.

This technology forms a 20–40㎛ thick NCM layer on the current collector, topped with an LCO layer 5–10㎛ thicker than the NCM layer. By adjusting the NCM to LCO weight ratio to between 60:40 and 80:20, it optimizes high-voltage stability and cycle life. Applicable to backup power for telecommunications, energy storage systems, transportation batteries, and lithium capacitor electrodes, it improves the balance between capacity and durability simply by combining existing cathode materials.

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Key Features:

• Bilayer cathode active material comprising Li(NixCoyMnz)O2 and LiCoO2 particles in a weight ratio of 60:40 to 80:20
• Li(NixCoyMnz)O2 layer with a thickness of 20 to 40㎛, where x is 0.6-0.8 and y and z are 0.1-0.3
• LiCoO2 layer formed 5 to 10㎛ thicker than the Li(NixCoyMnz)O2 layer
• Device including the bilayer cathode electrode, selected from telecommunications equipment, energy storage systems, and transportation

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