Lithium Nickel Composite Oxide Cathode with Aluminum Gradient

The patent applies local quality by creating a core-shell structure where the center region contains lithium nickel composite oxide with high nickel content for high capacity, while the outer peripheral region contains lithium nickel composite oxide with lower nickel content and higher aluminum content for enhanced stability. This spatial differentiation of composition allows each region to fulfill its specific function: the core provides capacity while the shell provides stability and safety.

The patent uses composite materials by combining lithium nickel composite oxide particles with different compositions to form a heterogeneous structure. The composite consists of inner core particles rich in nickel and outer shell particles rich in aluminum, creating a multi-component system that exhibits both high capacity (from nickel-rich core) and high stability (from aluminum-rich shell).

The patent applies local quality by concentrating aluminum addition in the outer peripheral region rather than uniformly distributing it throughout the particle. This localized aluminum enrichment at the surface specifically addresses the interface between electrode material and electrolyte, where degradation occurs most, thereby improving cycling characteristics while preserving the high-capacity nickel-rich core.

The patent applies preliminary action by pre-forming the core-shell structure with stabilized outer layers before battery assembly and use. The aluminum-rich outer region acts as a pre-established protective barrier that prevents degradation mechanisms from affecting the inner high-capacity core during cycling, thereby maintaining capacity retention over long-term use.

The patent applies local quality by restricting high aluminum content to the outer peripheral region of the particle, where it provides thermal stability and safety without significantly impacting the overall discharge capacity. The inner core maintains high nickel content for high capacity, while the outer shell provides safety functions, thus resolving the contradiction between safety and capacity.

The patent uses composite materials by creating a heterogeneous particle structure where aluminum-rich phases are combined with nickel-rich phases in specific spatial arrangements. The aluminum-containing outer shell provides thermal stability while the nickel-containing core provides discharge capacity, allowing the composite particle to exhibit both properties simultaneously.

The patent applies local quality by implementing a controlled concentration gradient of aluminum from the particle center to the surface, with higher aluminum content at the periphery. This non-uniform distribution is achieved through controlled precipitation processes during manufacturing, creating a core-shell structure that improves cycling characteristics and safety while using relatively simple wet chemistry methods.

The patent applies parameter changes by systematically varying the aluminum concentration as a function of radial position within the particle. The aluminum content increases from the center toward the surface, creating a gradient that optimizes both performance and stability. This parameter variation is controlled through precipitation conditions such as pH gradients or sequential addition of precursors.