Composite cathode active material with enhanced superlattice peaks, method for manufacturing the same, and cathode and lithium-ion battery comprising the same

Lithium-rich composite cathode material with enhanced superlattice peaks and stacking regularity

This technology improves the stacking regularity of lithium and transition metal layers within the crystal structure of lithium-rich layered composite active materials. By controlling specific XRD peak intensity ratios (I(20)/I(18)≥0.1, I(22)/I(20)≥0.78) and the full width at half maximum (FWHM) of superlattice peaks (020, 110) within defined ranges, it suppresses oxygen release reactions and maximizes reversible anionic redox reactions.

Conventional lithium-rich layered cathode materials suffer from high irreversible capacity due to structural instability caused by oxygen evolution during the first charge and the presence of stacking faults, which limits improvements in discharge capacity and energy density.

By using plate-like transition metal precursors to induce a regular arrangement of lithium and transition metal layers during synthesis, and performing rapid quenching after heat treatment to maintain high-temperature stable phases at room temperature, this technology maximizes the long-range order of the crystal structure. This ensures structural stability and can be utilized to reliably achieve the properties required for lithium secondary battery cathode materials.

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Key Features:

• Lithium-rich composite cathode active material with a layered structure containing an excess of lithium
• Crystal structure exhibiting specific XRD peak intensity ratios above defined values
• Active material featuring enhanced superlattice peaks to improve the stacking regularity of lithium and transition metal layers
• Manufacturing process using plate-like transition metal precursors and rapid quenching after heat treatment to induce regular arrangement

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