Diethylenetriamine directed the assembly of CoSe nanosheets layer by layer on N-doped carbon nanosheets for high performance lithium ion batteries.

CoSe nanosheets assembled layer by layer on N-doped carbon nanosheets (NC@CoSe) are designed and fabricated through a facile solvothermal process. The hexamethylenetetramine as the solvent and complexing agent promotes the accumulation of CoSe layer by layer. The long chain diethylenetriamine between the CoSe nanosheets provides buffer space and nanochannels for accelerating the Li transportation. The N-doped carbon nansheets in NC@CoSe provide effective conductive network during charge-discharge process. As an anode material for lithium-ion batteries, the NC@CoSe nanocomposites deliver a high specific capacity of 636 mAh g after 100 cycles at current density of 200 mA g, and 399 mAh g for 500 cycles at high current density of 5000 mA g.