Method for Manufacturing Cathode Active Material

High-Diffusion Lithium Cathode Material with Core-Shell Voids Formed via Nitrogen Atmosphere Heat Treatment

This technology involves heat-treating metal oxides in a nitrogen atmosphere prior to synthesizing lithium metal oxides. This process creates a secondary metal oxide with a lower oxygen ratio, resulting in a core-shell structure with internal voids and controlled grain size.

Conventional cathode materials often suffer from structural instability during charge-discharge cycles, low lithium diffusion coefficients, and high interfacial resistance, all of which lead to degraded electrochemical performance and shorter lifespans.

This technology heat-treats a primary metal oxide in a nitrogen-rich environment, such as NH3 gas, to refine grain size and produce a secondary metal oxide in the form of secondary particles containing internal voids. This is then calcined with lithium salt to synthesize the final lithium metal oxide. Suitable for high-power EV battery cells and fast-charging small batteries, the internal voids absorb volume changes during cycling, while the shortened diffusion paths accelerate lithium ion transport.

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Key Features:

• Heat-treating a primary metal oxide in a nitrogen-containing atmosphere to produce a secondary metal oxide with a lower oxygen ratio
• Calcining the secondary metal oxide with a lithium salt to produce the final lithium metal oxide
• A secondary metal oxide composed of aggregated primary particles, featuring a core and a surrounding shell
• A void region formed within the particle, positioned between the core and the shell to surround the core

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This invention was developed with support from the Samsung Science and Technology Foundation for research on developing high-capacity/fast-charging electrode materials using sequential gas-phase reactions.

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