On the Reactive Molten Salt Synthesis, Solubility and Na-Ion Storage Performance of Na₂Mo₂O₇

Abstract

A systematic investigation is conducted to evaluate the effect of temperature on the structural and morphological characteristics of Na2Mo2O7 produced by a facile and low-energy-intensive molten salt route using MoS2 and NaCl as precursors. The solubility of the Na2Mo2O7 product in water is confirmed by assessing the light absorption of the dissolved substance. The solubility values change between around 0.4 to 3.0 g l−1, depending on the temperature and pH level. The Na-ion storage performance of the molten salt-produced Na2Mo2O7 is characterized by cyclic voltammetry, charge–discharge and electrochemical impedance spectroscopy tests. Nanostructuring of Na2Mo2O7 through high-energy ball milling with graphene nanosheets decreases the interface impedance, enhancing the pseudocapacitive performance of the material.