Li2MnO3/Graphene Composite Anode Material for Lithium Ion Battery

Abstract

Lithium ion batteries have been popularly used as the rechargeable power sources in consumer electronics due to their high energy storage density since the first commercial lithium ion battery launched by Sony in 1991. Graphite is still commonly used as anode material for commercial Lithium ion batteries due to its low redox potential close to Li+/Li, good cycling stability, low cost, and environmental friendliness.[1] However, the performance of current lithium ion batteries, which use graphite as the anode material, cannot satisfy requirements of fast charge Lithium ion batteries. The volume expansion/contraction of the graphite associated with the lithium insertion and extraction process, which results in loss of inter-particle electronic contract, consequently, lead to poor cycling stability. Another consideration of graphite is their safety caused from lithium dendrite formation due to its low Lithium intercalation potential at about 0 V (vs. Li/Li+). [2] The search for new anode materials for lithium ion batteries has been an important way to satisfy the ever-growing demands for better performance with higher energy/power densities, improved safety and longer cycle life. Recently, Li2MnO3 was investigated as an anode material for lithium ion battery.[3] Li2MnO3 exhibits much higher capacity than conventional carbon-based materials and a very stable cycling performance. In this work, as-prepared Li2MnO3/graphene composite material shows the enhanced reversible specific capacity and the rate performance compared with that of pristine Li2MnO3 . It was found that the conductivity of Li2MnO3/graphene was significantly improved by forming a conductive graphene network throughout the insulating Li2MnO3.