A mixed polyanion NaFe1−x(VO)xPO4 glass-ceramic cathode system for safe and large-scale economic Na-ion battery applications

Abstract

In this paper, highly efficient mixed polyanion NaFe_1−x(VO)_xPO₄ series of glass-ceramic cathode samples have been synthesized for use in sodium-ion batteries with good specific capacity and capacity retention. Electrochemical experiments show that the best-conducting NaFe_0.5(VO)_0.5PO₄ (x = 0.5 mol%) glass-ceramic sample delivers the highest capacity for both the 1st and 20th cycles since it exhibits two distinct voltage plateaus (3.2 V and 2.8 V, respectively) together with a discharge capacity retention (69.66%) even at 10C compared with all the other investigated samples. These desirable results related to electrochemical performance make the mixed polyanion NaFe_1−x(VO)_xPO₄ series of glass-ceramic cathode networks suitable for large-scale economic sodium-ion battery applications.