Development of electrically conductive ZrO2-CaO-Fe2O3-V2O5 glass and glass-ceramics as a new cathode active material for Na-ion batteries with high performance

Glass-ceramics xZrO2•10Fe2O3•(90-x)V2O5 with ‘x’ between 0 and 30 mol% yZrO2･(20-y)CaO･10Fe2O3･70 V2O5 glass ‘y’ 20 mol%, respectively abbreviated as xZFV yZCFV, before after heat treatment at 500 °C for 100 min, were evaluated potential cathode-active materials sodium-ion batteries (SIBs). Relationships physical properties local structure of yZCFV glass-ceramics investigated by 57Fe-Mössbauer spectroscopy, V K-edge X-ray absorption near edge (XANES), diffractometry (XRD), DC four-probe method differential thermal analysis (DTA). SIBs containing heat-treated showed the highest discharge capacity 153 mA h g−1 under a current density 50 mA•g−1, which exhibited high electrical conductivity 1.8 × 10−2 Scm−1. Precipitation V0.05Zr0.95O2 Fe2V4O13 nanoparticles confirmed from XRD pattern 20ZFV glass, consistent lower energy pre-edge peak 5467 eV in XANES spectrum. This result is associated reduction vanadium ions VV to VIV. It concluded that precipitation stable bronze phases structural stability effectively enable SIB these materials.