MgMoO4 as an anode material for lithium ion batteries and its multi-electron reaction mechanism

Abstract

Single-phase magnesium molybdate, MgMoO₄, is successfully synthesized by a facile sol-gel method. Attributed to the multielectron reaction and the synergistic effect of the elements molybdenum (Mo) and magnesium (Mg), the MgMoO₄ electrode exhibits excellent electrochemical properties. After activation, benefiting from the decrease in particle size and the uniform nanosphere morphology, the MgMoO₄ electrodes can deliver a stable high specific capacity of about 1060 mA h g⁻¹ at a current density of 100 mA g⁻¹ after 600 cycles. Based on the important role of the activation process, electrochemical impedance spectroscopy (EIS), scanning electron microscopy (SEM) and scan rate cyclic voltammetry (CV) measurement methods were employed to reveal the effect of the activation process on the electrochemical behavior of the electrode material. Furthermore, by combining the in situ X-ray diffraction (XRD) and ex situ X-ray photoelectron spectroscopy (XPS) results, we illustrate the lithium storage mechanism of the MgMoO₄ electrode in detail.