High capacity MoO3/rGO nanocomposite anode for lithium ion batteries: an intuition into the conversion mechanism of MoO3

Abstract

MoO₃ is a potential anode material for Li-ion batteries (LIBs) because of its high theoretical capacity (1117 mA h g⁻¹). The major hurdles in realizing this high capacity are its low conductivity and large volume variations during intercalation/de-intercalation processes. To mitigate these shortcomings, we have synthesized reduced graphene oxide (rGO) wrapped MoO₃ nanoparticles (NPs). This involves the synthesis of MoO₃ NPs as the first step and then subjecting the synthesized MoO₃ NPs to hydrothermal treatment along with graphene oxide (GO) sheets to form rGO wrapped MoO₃ NPs. Electrochemical impedance spectra show that a 13% MoO₃/rGO nanocomposite has the least conductive resistance among the different nanocomposites. Several physicochemical characterization techniques have been used to confirm the desired state of the obtained material. Ex-XRD studies were carried out to inspect the mechanism of MoO₃ and found that it initially follows a simple lithiation/delithiation mechanism and later it adopts a conversion mechanism. The new architecture exhibits an excellent electrochemical performance by displaying a high first specific discharge capacity value (984 mA h g⁻¹) and remarkable stability (901 mA h g⁻¹ even after 100 cycles).