Cathode active material with a heteroatom-doped surface layer, and manufacturing method thereof

High-nickel cathode precursor combining an outermost heteroatom-doped shell with a-axis elongated primary particles

This technology is a structural design that maximizes lithium-ion mobility in high-nickel cathode active materials by doping heteroatoms such as tungsten (W), molybdenum (Mo), and tantalum (Ta) only on the particle surface, while controlling the crystal structure and primary particle aspect ratio of both the interior and surface.

While high-nickel cathode active materials offer high capacity, they suffer from crystal structure instability during repeated charge-discharge cycles. Furthermore, surface side reactions have historically limited cycle life and caused a gradual decline in discharge capacity.

This technology differentiates the composition of the secondary particle's core and surface, doping heteroatoms in a concentration gradient only in the outermost 2–20% of the radius, and forming primary particles on the surface with a longer a-axis length than those in the interior. This enhances lithium-ion conductivity and induces a cation ordering structure, improving thermal stability and cycle life. Applicable to mass production of high-nickel NCM/NCA cathode precursors for EVs and high-capacity pouch cells, it allows for long-life cathode materials while limiting doping elements to the surface.

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Key Features:

• Cathode active material precursor comprising a first secondary particle composed of a plurality of first primary particle groups
• A first core consisting of the chemical formula Ni1-xM1x(OH)2 and a first surface layer of the chemical formula Ni1-y-zM1yM2z(OH)2 containing M2 heteroatoms
• A first surface layer doped with heteroatoms, provided at a thickness of 2% to 20% of the precursor's average radius
• Primary particles in the first surface layer provided with a longer a-axis length than the primary particles in the first core

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