N-doped carbon-encapsulated MnO@ graphene nanosheet as high-performance anode material for lithium-ion batteries

MnO is a promising anode material for lithium-ion batteries because of its high capacity and abundant source, yet some critical issues such as the low conductivity and huge volume changes during cycling are still challenging its real application. Here, a facile strategy is proposed to realize the uniform decoration of MnO nanoparticles (20-40 nm) on graphene encapsulated with N-doped carbon layer (MnO@ rGO/NC). In this structure, graphene acts as a robust and conductive platform for the anchoring of MnO nanoparticles and the outer N-doped carbon can further guarantee the structural integrity and conductivity of the composite. When evaluated as anode materials in lithium-ion batteries, the prepared MnO@ rGO/NC composite with an optimized amount of MnO (58%) exhibits stable cycling performance and superior high rate capability, which delivers a reversible capacity as high as 989.8 mA h g(-1) at 0.2 A g(-1) after 130 cycles. The design and synthetic strategy presented in this work can be extended to other anode materials with large capacity, which endure large volume expansion and low conductivity during the charge-discharge processes.