Superior Sodium Storage Properties in the Anode Material NiCr₂ S₄ for Sodium-Ion Batteries: An X-ray Diffraction, Pair Distribution Function, and X-ray Absorption Study Reveals a Conversion Mechanism via Nickel Extrusion.

ABSTRACT: The pseudo-layered sulfide NiCr₂ S₄ exhibits outstanding electrochemical performance as anode material in sodium-ion batteries (SIBs). The Na storage mechanism is investigated by synchrotron-based X-ray scattering and absorption techniques as well as by electrochemical measurements. A very high reversible capacity in the 500th cycle of 489 mAh g^-1 is observed at 2.0 A g^-1 in the potential window 3.0-0.1 V. Full discharge includes irreversible generation of Ni⁰ and Cr⁰ nanoparticles embedded in nanocrystalline Na₂ S yielding shortened diffusion lengths and predominantly surface-controlled charge storage. During charge, Ni⁰ and Cr⁰ are oxidized, Na₂ S is consumed, and amorphous Ni an

SUBMITTER: Hartmann F 

PROVIDER: S-EPMC11468954 | biostudies-literature | 2021 Nov

REPOSITORIES: biostudies-literature