Abstract:

Owing to the shortage of lithium resources, we investigated the sodium-ion storage device using MoO₃ as the negative electrode materials. MoO₃ was prepared through a simple method and characterized by X-ray diffraction(XRD), scanning electron microscopy(SEM) and transmission electron microscopy(TEM). MoO₃ was used as the negative electrode materials for electric energy storage devices using Na⁺-based organic electrolytes. The charge storage mechanism at the MoO₃ negative electrode was investigated by cyclic voltammetry and galvanostatic charge-discharge tests. A new type of electric energy storage devices was constructed with MoO₃ as negative materials and activated carbon(or graphite) as positive materials. The electrochemical properties were studied in 1 mol/L NaPF₆-propylene carbonate(PC). The MoO₃/AC and MoO₃/graphite devices owns the voltage ranges of 0~3.2 V and 0~3.5 V, energy densities of 31.6 Wh/kg and 53 Wh/kg, respectively. The long-cycling stabilities of both devices are superior to the AC/AC symmetric capacitor obviously. This kind of energy storage devices would be a good substitute for lithium-ion batteries.

Key words: molybdenum trioxide, activated carbon, graphite, negative electrode materials, electric energy storage devices