The role of lithiation temperature in tuning structural and electrochemical properties of Ni-Rich cathodes with different nickel concentrations

Ni-rich cathode materials are highly promising for high-performance lithium-ion batteries, owing to their superior overall electrochemical properties. The electrochemical performance of these materials is intimately linked to the degree of ordered development within their layered structure. However, the optimal lithiation calcination temperature for achieving highly ordered layered structures varies among Ni-rich materials with different nickel contents, and this critical parameter has not been thoroughly investigated. This study systematically addresses this gap by selecting four precursors with distinct nickel contents and subjecting them to lithiation calcination across a series of stepwise temperatures. Through in-situ high-temperature X-ray diffraction (XRD) and XRD Rietveld refinement, we deciphered the dynamic evolution characteristics of layered structures during lithiation in materials with varying nickel contents. Furthermore, we clarified the regulatory effect of lithiation temperature on the materials’ structural order and concurrently evaluated their electrochemical performance. Ultimately, this research clarifies the intrinsic relationship between lithiation temperature, layered structure characteristics, and electrochemical performance, offering significant guidance for the precise design and preparation of high-performance Ni-rich cathode materials.