The electrochemical performanceand multielectron reaction mechanism of NiV2O6 as anovel anode material for lithium-ion batteries

Abstract

Based on the existence of multiple valence states of Ni and V, the single-phase nickel vanadium bimetal oxide NiV2O6 is successfully synthesized by asimple sol-gel method. Benefiting from the multielectron reaction of nickel (Ni) and vanadium (V), as novel anode materials of lithium-ion batteries (LIBs), the NiV2O6 electrode exhibits excellent electrochemical performance. After activation, attributed to the decrease in the particle size and an increased pseudocapacitance contribution, the electrode material exhibits a highly stable reversible capacity. At a small current density of 0.1 A g−1, a stable discharge specific capacity of around 1200 mA h g−1 can be observed, which is more than three times the capacity of the commercial graphite anode. Using electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM) measurement methods, we discuss the function of the activation process. To explore the discharge/charge process, based on in situ X-ray diffraction (XRD) measurements, combined with the X-ray photoelectron spectroscopy (XPS) and SEM results, we analyze the charge/discharge reaction mechanism of the NiV2O6 electrode in detail for the first time. In addition, a full cell is employed to confirm the practicality of the NiV2O6 anode material.