Exploring the electrochemical properties of Na2S -V2O5-P2O5 glass-ceramic nanocomposites as a cathode for magnesium-ion batteries

•Na2S –V2O5–P2O5 glass-ceramic nanocomposites were prepared.•The 12 h cell achieved a reasonable capacity and a coulombic efficiency of 78℅ after 100 cycles at 55 °C.•We conclude that samples are a good candidate for solid state batteries. High charge density of Mg yields the sluggish kinetic of Mg2+ insertion/extraction in the host lattice, this is a main difficulty to realize the commercial applications. As an attempt to overcome this challenge, a glass sample (NSVP) was prepared following the molar ratio (13.5 Na2S – 32.5 V2O5–54 P2O5) mol% using the melt-quenching process in addition to its corresponding glass-ceramic nanocomposites. All samples were employed in a fully assembled Mg ion coin cell at both room temperature and 55 °C. The CV, CA, GCD and EIS were reported for all the present samples. The diffusion coefficient of Mg ions ~10-16 indicates that Mg ion diffusion in the prepared host structures is moderately favorable. The 12 h sample achieved the best electrochemical performance at both temperatures (e.g., the highest initial capacity ~86 mAh g-1, energy density ~11 Wh Kg-1 at 55 °C and high stability). Its coulombic efficiency was 78% at 55 °C after 100 cycles. This can be due to smaller crystalline size (42 nm) and/or due to the flexible structure of β-VOPO4 having corner-sharing VO5 pyramids along with PO4 tetrahedra, similar to VO5F octahedra and PO4 tetrahedra in Na3V2O2F(PO4)2.