Graphene-wrapped MnCO3/Mn3O4 nanocomposite as an advanced anode material for lithium-ion batteries: Synergistic effect and electrochemical performances

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.