Metal-organic framework derived small sized metal sulfide nanoparticles anchored on N-doped carbon plates for high-capacity energy storage.

ZnS nanoparticles wrapped in N-doped mesoporous carbon nanosheets are prepared from metal-organic frameworks through a simple co-pyrolysis process. In the composite interface, ZnS nanoparticles are directly loaded on the carbon and form a mesoporous structure, thus providing fast electron and ion dual transfer routes, and efficient electrode reaction kinetics. In addition, the heteroatom N-doping and the small-sized ZnS with embedded carbon can provide more active sites and stable electrode kinetics for electrochemical reactions. As a consequence, this material shows a capacity of 160 mA h g-1 at 1 A g-1, and retains 92.9% of its initial capacity after cycling for 1000 times at 5 A g-1. In the assembled asymmetric device, an energy density of 45.5 W h kg-1 is obtained. Such superior properties and facile production process of the metal-organic framework-derived composite show great potential in energy storage.