Spinel Cathode Active Material With Surface Oxides for Cycling Stability

The patent applies local quality by introducing a core-shell structure where the core maintains the highly crystalline spinel structure for structural integrity, while the shell layer provides protective functionality to enhance cycling stability. This localized differentiation of material properties at different spatial regions (core vs. surface) resolves the contradiction between maintaining crystalline uniformity and improving reliability.

The patent employs composite materials by combining the lithium nickel manganese oxide spinel core with a shell layer comprising lithium transition metal oxide or lithium phosphate. This composite structure integrates the advantages of both materials: the core provides high capacity and crystalline structure, while the shell enhances cycling stability and protects against degradation, thereby resolving the contradiction between manufacturing precision and reliability.

The patent applies segmentation by dividing the material into core particles and shell layers, where the core maintains the homogenous mixture achieved through mechanical mixing, and the shell layer is precipitated or deposited onto the core surfaces. This segmented approach preserves mixture homogeneity while the controlled shell formation improves particle morphology and tap density.

The patent uses preliminary action by first preparing the homogenous mixture of starting materials through mechanical mixing to form the core, then subsequently forming the shell layer through controlled precipitation or deposition. This sequential approach ensures mixture homogeneity is established before shell formation, allowing both requirements to be satisfied.

The patent applies beforehand cushioning by incorporating a shell layer that protects the core material from excessive oxygen loss during high-temperature annealing. The shell acts as a protective barrier that allows the core to undergo necessary thermal treatment for spinel morphology development while minimizing harmful oxygen loss, thus cushioning against substance loss before it becomes problematic.

The patent uses parameter changes by optimizing the annealing temperature and atmosphere parameters to achieve spinel morphology while controlling oxygen loss. By carefully adjusting these processing parameters and incorporating a protective shell, the patent balances the need for high-temperature treatment with the need to prevent excessive oxygen loss.