An advanced CoSe embedded within porous carbon polyhedra hybrid for high performance lithium-ion and sodium-ion batteries

•A novel composite containing CoSe and porous carbon polyhedra was fabricated.•The composite was used as anodes of lithium ion batteries and sodium ion batteries.•The composite exhibits high specific capacity and superior cycling stability.

A novel composite containing CoSe and porous carbon polyhedra (PCP), denoted as CoSe@PCP, was successfully synthesized using Co-based zeolitic imidazolate framework (ZIF-67) as precursor through a two-step method, including carbonization of ZIF-67 and subsequent selenization. The field-emission scanning electron microscopy and transmission electron microscopy characterizations confirm that CoSe nanoparticles are uniformly dispersed in PCP. When the CoSe@PCP was used as anode material for lithium-ion batteries, it exhibits superior performance with a high reversible capacity of 675 mAh g−1 at 200 mA g−1 after 100 cycles and 708.2 mAh g−1 at 1 A g−1 after 500 cycles as well as excellent cycling stability. Additionally, the CoSe@PCP also demonstrates excellent performance as anode material for sodium-ion batteries. A reversible capacity of 341 mAh g−1 can be obtained over 100 cycles at 100 mA g−1 with high cycling stability. The excellent battery performance of CoSe@PCP should be attributed to the synergistic effect of nanostructured CoSe and PCP derived from ZIF-67, in which the nanostructured CoSe possesses high reactivity towards lithium and sodium ions and the PCP can provide a continuous conductive matrix to facilitate the charge transfer and an effective buffering to mitigate the structure variation of CoSe during cycling.

Graphical abstractDownload high-res image (111KB)Download full-size image