PolyanionNaNi_1 − xCu_xPO₄ glass and glass-ceramic cathode network: Structure with improved electrochemical performance

PolyanionNaNi_1 − xCu_xPO₄ glass and glass-ceramic networks are prepared by Melt-quenching and after heat treated for 5 h at its T_c, regarded as probable cathode composite material for Na-ion batteries (SIBs). The intensity variations arrived from XRD traces, revealed that the phases NaNi₄(PO₄)₃ (ICSD 60-964), NaCu(PO₄) (ICSD 581-303), and Na₂CuNi(PO₄)₂ (ICSD 20-22594) which are precipitated during heat treatment is primarily caused by the partial substitution of tetrahedral PO₄ and CuO₆ sites with NiO₆ structural active sites in the glass-ceramic network resulting to accommodate sudden volume changes, and therefore diffusion of Na⁺ ions will be improved along with fast rate capability and voltage for longer durations as reflected in SEM image analysis. The cyclic voltammogram of half-cell of best conducting NaNi_0.3Cu_0.7PO₄ glass-ceramic cathode with a voltage range of 0.2 to 4 V and 100 V/S cycles noted to achieve lowest cell polarization (0.41 V) with best capacity retention of discharge (96%) up to 1000 cycles.