Unveiling the Reaction Mechanism during Li Uptake and Release of Nanosized "NiFeMnO₄": Operando X-ray Absorption, X-ray Diffraction, and Pair Distribution Function Investigations.

ABSTRACT: Here, we report that the trimetallic nanosized oxide NiFeMnO₄ consists of a mixture of NiO and a strained cubic spinel phase, which is clearly demonstrated by analysis of the pair distribution function (PDF) and synchrotron X-ray data. Such a finding can easily be overlooked by using only inhouse X-ray powder diffraction, leading to inaccurate assumption of the stoichiometry and oxidation states. Such advanced characterization is essential because a homogeneous distribution of the elements is observed in energy-dispersive X-ray spectroscopy maps, giving no hints for a phase separation. Cycling of the sample against Li delivers a high reversible capacity of ≈840 mAh/g in the 50th cycle. Operando X-ray absorption spectroscopy (XAS) experiments indicate that ≈0.8 Li/fu is consumed

SUBMITTER: Permien S 

PROVIDER: S-EPMC6649279 | biostudies-literature | 2019 Jan

REPOSITORIES: biostudies-literature