Integrated design of sandwich-like C@MoS2@C nanospheres as active anode material for lithium-ion batteries

Molybdenum disulfide (MoS2) is gaining popularity as an active material for constructing anode in rechargeable lithium-ion batteries. However, the low conductivity, poor cycle stability and charge-discharge rate performance are still the main obstacles hindering its practical applications. In the present work, a novel structure of sandwich-like N-doped carbon@MoS2@N-doped carbon hierarchical nanospheres (C@MoS2@C) is rationally designed, where a hollow N-doped carbon hierarchical microsphere served as a core and ultrathin N-doped carbon coated "sandwiched" MoS2 nanosheets (NSs) as a shell. The inner carbon skeleton serves as a template for the in-situ growth of MoS2 NSs, whereas the outside carbon layers protect the MoS2 layer with high structural stability. The 3D fiber carbon nanospheres made from KCC-1 have high specific surface area and large pore diameter, which can shorten the ion diffusion path and accelerate the reaction kinetics. Additionally, the close contact between MoS2 and the two carbon layers not only improves the conductivity of electrode but also enhances the reversibility of the conversion reaction of Mo/Li2S to MoS2 by suppress the oxidation of Li2S to polysulfides. As a sequence, the as-prepared C@MoS2@C nanospheres exhibit a remarkable initial discharge capacity, excellent cycling stability, and outstanding rate performance. We believe that the as-prepared composite material may offer some potential applications as anodic materials for efficient lithium batteries.