One-step synthesis of carbon-coated monocrystal molybdenum oxides nanocomposite as high-capacity anode materials for lithium-ion batteries

Abstract

Benefitting from higher specific capacities, acceptable cost, nontoxicity and unique crystal structures, the molybdenum oxides have been studied as the anode materials for lithium ion batteries (LIBs). Herein, a direct current (DC) arc-discharge plasma technique has been developed to in-situ synthesize carbon-coated monocrystal molybdenum oxides ((MoO3NRs/MoO2NPs)@C) nanocomposites, using coarse MoO3 bulk as the raw material and methane (CH4) gas as the carbon source. It is indicated that crystallographic traits of MoO3 and MoO2 nuclei give rise to an anisotropic growth of monocrystal MoO3 nanorods (NRs) along <100> direction and an isotropic growth of monocrystal MoO2 nanoparticles (NPs). The carbon shells on MoO3/MoO2 nanostructures are generated from the absorption of carbon atoms in surrounding atmosphere or the release of supersaturated carbon atoms in MoOC solid solution. Unique constitution and pseudo-capacitive behavior of (MoO3NRs/MoO2NPs)@C bring merits to excellent cycling performance and rate capability, i.e. a remarkable specific capacity of 840 mA h⋅g−1 after 100 cycles at a current density of 0.1 A g−1 and a retained capacity of 210 mA h⋅g−1 at 6.4 A g−1. This work has offered a simple and efficient approach to fabricate the carbon-coated molybdenum oxides nanostructures for promising anode materials of LIBs.