Design of low-cost, high-activity cathode materials with unique microstructures for lithium-ion batteries

High-Rate NCA Cathode Active Material Nanorod-Structured via Trace Indium Doping

This technology is a cathode material that maximizes ion and charge transfer efficiency by doping a specific amount of indium (In) onto the surface of a lithium-nickel-cobalt-aluminum (NCA) composite oxide, transforming its irregular polygonal particle structure into nanorods with an aspect ratio of 5–10 to shorten lithium-ion diffusion paths.

Conventional NCA cathode active materials suffer from long lithium-ion diffusion paths and high ion-transfer resistance due to their irregular polygonal primary particle structure and numerous grain boundaries. These limitations lead to performance degradation during fast charging and reduced cycle life.

This technology synthesizes indium-doped nanorod cathode active materials with an aspect ratio of 5–10 while maintaining a layered structure with an interplanar spacing (D003) of 0.4–0.5 nm by mixing a transition metal precursor with a lithium precursor and indium(III) acetylacetonate, followed by calcination in an oxygen atmosphere at 700–740°C. Manufactured via simple solid-state mixing and a single calcination step, it is ideal for fast-charging EV cells, high-power power tool batteries, and communication device power supplies, enhancing rate capability with minimal dopant costs.

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Key Features:

• Cathode active material with a composition of Lix(NiyCozAluMw)O2, where the lithium transition metal composite oxide is doped with In
• Lithium transition metal composite oxide satisfying molar ratios of 0.82–0.85 nickel, 0.14–0.18 cobalt, 0.005–0.01 aluminum, and 0.0006–0.0008 indium
• Cathode active material particles in the form of nanorods with an aspect ratio of 5 to 10 and an average diameter (D50) of 1.0–7.0㎛
• Step of solid-state mixing a transition metal compound precursor powder with a lithium precursor and indium(III) acetylacetonate, followed by calcination

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This invention was developed with support from the Ministry of Science and ICT’s Materials Computation program.

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