Nickel Orthorhombic Cathode Coating for Capacity and Cycle Stability

The patent applies composite materials by creating a core-shell structure where the center part consists of a lithium composite oxide with high capacity (such as layered rock-salt structure) and the covering part consists of a different lithium composite oxide with stable crystal structure (such as orthorhombic structure). This composite structure allows the high-capacity material to function while being protected by the stable surface material, thereby achieving both high battery capacity and stability during repeated charging and discharging.

The patent applies local quality by creating different material properties in different regions of the positive electrode active material. The center part has high reactivity and high capacity characteristics, while the covering part has low reactivity and high stability characteristics. This spatial differentiation of material properties allows the bulk material to provide high energy density while the surface material protects against electrolyte decomposition.

The patent applies the nested doll principle by creating a core-shell structure where the high-capacity material is nested inside the stable surface material. The covering part completely encloses the center part, forming a protective shell that maintains stability while allowing ionic transport. This nested structure ensures that the active material is fully protected without requiring external coating that would block active sites.