Designed cross-linking nanoporous Zn0.76Co0.24S @C-ZIF-Zn0.76Co0.24S core-shell nanosheet arrays on nickle foam for battery-type electrodes with high performance electrochemical energy storage

Abstract

Ternary metal sulfide as a novel electrode material in energy storage receives tremendous attention, but there are few reports about zinc cobalt sulfide as eletrode material for electrochemical energy storage devices. However, the problem of structural collapse for the zinc cobalt sulfide caused by severe volume change restrict its cycling stability and rate capability. For solving the problem, a new type structure of metal–organic frameworks (MOFs)-derived nanoporous Zn0.76Co0.24S nanoparticles with a carbon layer perfectly decorated on a Zn0.76Co0.24S nanosheet arrays is raised. Benefiting from the core–shell structure and the carbon derived from MOFs, the Zn0.76Co0.24S@C-ZIF-Zn0.76Co0.24S core-shell nanosheet arrays (Zn0.76Co0.24S CSNSAs) electrode has a high specific capacity (1202 C g−1 at 1 A g−1), good rate capability and cycling stability (92% capacity retention after 5000 cycles at 10 A g−1). What’s more, the energy storage device assembled with Zn0.76Co0.24S CSNSAs achieves superior energy density (79.2 Wh kg−1 at 625 W kg−1), exhibiting excellent cycling stability (97% over 2000 cycles). Compared to pristine Zn0.76Co0.24S, the new type structure electrode exhibits a significantly enhanced charge storage property. With a novel synthesis and the outstanding electrochemical properties, this creative design renders Zn0.76Co0.24S CSNSAs a promising anode material for advanced energy storages.