LiCoO2 Cathode Composition for Stable High-Voltage Cycle Life

The patent applies local quality by creating distinct compositional regions within the lithium cobalt oxide crystal structure. The surface region contains magnesium at 0.5-10 atomic % while the inner region contains nickel at 0.5-10 atomic %, with fluorine and aluminum distributed throughout. This spatial differentiation of compositional properties stabilizes the crystal structure during charge-discharge cycles while maintaining discharge capacity, resolving the contradiction between reliability and compositional stability.

The patent implements beforehand cushioning by incorporating magnesium, fluorine, aluminum, and nickel into the lithium cobalt oxide structure before operation. These elements create a stabilized crystal structure that prevents oxygen release and suppresses thermal runaway even when charged to high voltages. The compositional modifications act as preventive measures that cushion against thermal instability, allowing high energy output without increasing thermal runaway risk.

The patent merges multiple functional elements (magnesium, fluorine, aluminum, and nickel) into a single integrated lithium cobalt oxide positive electrode material. Rather than applying separate surface coatings or composite structures, all modifications are incorporated into the bulk crystal structure, achieving degradation resistance through a unified material design. This merging approach improves cycle performance while avoiding the manufacturing complexity of multi-layer composite structures.