Graphene-wrapped MnCO_(3)/Mn_(3)O_(4) nanocomposite as an advanced anode material for lithium-ion batteries: Synergistic effect and electrochemical performances

摘要

Developing new electrode materials with a high specific capacity for excellent lithium-ion storage properties is very desirable.The MnCO_(3)/Mn_(3)O_(4)nanoparticles with uniform size(about 50 nm)and shape which are wrapped with graphene have been successfully synthesized via the one-step method for anode material of lithium-ion batteries.The as-prepared graphene-wrapped MnCO_(3)/Mn_(3)O_(4)nanocomposite exhibits remarkable electrochemical performance,including high reversible specific capacity,outstanding cycling stability,and excellent rate capability in comparison with the bare MnCO_(3)and MnCO_(3)/Mn_(3)O_(4)nanocomposite.This is because the synergistic effect of MnCO_(3)and Mn_(3)O_(4)nanoparticles and graphene nanosheets act as both electron conductors and volume buffer layers.From the scanning electron microscopy(SEM)analysis,we confirmed that the morphology and structure of the composite are preserved after 200 cycles.This further confirms that graphene-wrapped MnCO_(3)/Mn_(3)O_(4)nanocomposite acts as a stable template for reversible lithium-ion intercalation/deintercalation.