2D layered mesoporous MoO2/rGO composites for high performance anode materials in lithium-ion battery

Abstract

Transition metal oxides are great promising anode materials with much higher theoretical electrochemical capacities for lithium ion battery compared with the commercialized carbon materials while serious capacity fading and poor cycle stability caused by large volume change and sluggish kinetics must be addressed for their practical application. Herein, we demonstrated a novel strategy to synthesize 2D layered mesoporous-MoO2/graphene (meso-MoO2/rGO) electrode materials using KIT-6/rGO as a template and ammonium molybdate as a precursor via a nanocasting method. By combining graphene with MoO2 and endowing it mesoporous structure, 2D layered meso-MoO2/rGO electrode materials are expected to show superior electrical conductivity, structured flexibility, and chemical stability, which may provide uninhibited conducting pathways for fast charge transfer and transport between oxide nanoparticles and graphene. In addition, mesoporous MoO2 is also anticipated to optimize Li+ transport in pore walls and fast electrolyte transport within highly ordered mesopores. As a result, meso-MoO2/rGO electrode materials possess an ordered mesoporous structure with a superior electrochemical performance. The electrochemical performances were examined using galvanostatical charge-discharge, cyclic voltammetry, and electrochemical impedance spectroscopy (EIS) techniques. Benefiting from the combining effects of mesoporous MoO2 and 2D layered graphene, meso-MoO2/rGO electrode materials alleviate the volume effect and give an enhanced discharge and charge capacity and robust cycle stability. The meso-MoO2/rGO composite delivers the first discharge capacity of 1160.6 mA h g−1 and its reversible capacity is 801 mA h g−1 after 50 cycles, making it promising for potential uses as high performance anode materials in lithium-ion battery.