Vertically aligned nanosheets with MoS2/N-doped-carbon interfaces enhance lithium-ion storage

Molybdenum disulfide (MoS2) has received much attention as a promising anode material for lithium-ion batteries (LIBs), because it can deliver a high specific capacity generated from the complex conversion reactions. But, the poor intrinsic electrical conductivity and the shuttling of intermediate products (lithium polysulfides, LiPSs) during cycling lead to poor electrochemical performances. Herein, vertically aligned MoS2 nanosheets on nitrogen-doped carbon nanosheets (MoS2-NC hybrids) are constructed by a simple two-step synthesis strategy as anode materials with a high-capacity and long cycling life for LIBs. Apart from being a conductive carbon matrix, the N-doped carbon serves as a reservoir to hold the LiPSs, thereby effectively suppressing the shuttling of LiPSs. The density functional theory (DFT) calculations fully testify that the MoS2-N-doped carbon interface not only could show strong adsorption for LiPSs and Li atom, but also provide a small diffusion energy barrier for Li+. Consequently, the MoS2-NC hybrids as LIBs anode materials deliver a high discharge specific capacity of 995 mAh g(-1) at a low current density of 0.2 A g(-1) after 300 cycles and a high-capacity retention of 815 mAh g(-1) at a high current density of 1 A g(-1) after 500 cycles.