Mixed polyanion Na2O-CuO-V2O5-P2O5 glass and glass ceramic cathode network: Relationship between structure and electrochemical performance

Abstract

This investigation presents mixed polyanion G-NaCu1 − x(VO)xPO4 (x = 0.1, 0.3, 0.5,0.7and 0.9 mol%) glass-based cathode material network prepared using the melt-quenching process followed by heat-treating at its Tcfor 5h to form its glass-ceramic(GC- NaCu1 − x(VO)xPO4). The best crystalline NaV2O5 (ICSD 760908) NaCu(PO4)(ICSD 581303), and Na2Cu(P2O7)(ICSD 556822) phases precipitated in the glass network during crystallization will accommodate sudden volume changes, resulting to trigger the fast diffusion of Na+ ions in the glass-ceramic network leading to fast rate capability and voltage for longer durations. The lowest charge transfer resistance Rct = 7.086x103Ω from 1st to 1000 cycles and highest retention of discharge capacity (99.71%) when the current rate is decreased from 10C to 0.1C, determines its long-term cycle life stability and rate capability more than other crystalline compounds.