Diethylenetriamine directed the assembly of Co0.85Se nanosheets layer by layer on N-doped carbon nanosheets for high performance lithium ion batteries

Abstract

Co0.85Se nanosheets assembled layer by layer on N-doped carbon nanosheets (NC@Co0.85Se) are designed and fabricated through a facile solvothermal process. The hexamethylenetetramine as the solvent and complexing agent promotes the accumulation of Co0.85Se layer by layer. The long chain diethylenetriamine between the Co0.85Se nanosheets provides buffer space and nanochannels for accelerating the Li+ transportation. The N-doped carbon nansheets in NC@Co0.85Se provide effective conductive network during charge-discharge process. As an anode material for lithium-ion batteries, the NC@Co0.85Se nanocomposites deliver a high specific capacity of 636 mAh g−1 after 100 cycles at current density of 200 mA g−1, and 399 mAh g−1 for 500 cycles at high current density of 5000 mA g−1.