Probing the Mysterious Behavior of Tungsten as a Dopant Inside Pristine Cobalt‐Free Nickel‐Rich Cathode Materials

Nickel-rich cathode materials with small amounts of tungsten (W) dopants have attracted extensive attention in recent years. However, the chemical state, crystalline form, compound chemistry, and location W these layered cathodes are still not well-understood. In this study, missing structural properties determined through a combination macro-, to atomic-sensitive characterization techniques density functional theory (DFT). W-doped LiNiO2 (LNO) particles, prepared mechanofusion coprecipitation methods, used probe changes structure W-species. The results indicate that is mainly distributed on surfaces inside grain boundaries secondary regardless doping method. Electron energy loss spectroscopy (EELS) mapping confirms simultaneous presence W, O, without Ni as well W- O-rich regions very surface. W-rich areas found be two forms, amorphous. This paper suggests kinetically stabilized-Li4+xNi1-xWO6 (x = 0, 0.1) possibility LixWyOz phases LNO which consistent electron microscopy, X-ray absorption diffraction data. multiple roles complex microstructure discussed considering distribution.