Hierarchically porous hexagonal microsheets constructed by well-interwoven MCo2S4 (M = Ni, Fe, Zn) nanotube networks via two-step anion-exchange for high-performance asymmetric supercapacitors

A general controllable two-step anion-exchange method results in novel hierarchically porous hexagonal thin microsheets constructed by well-interwoven nanotubes (NTs), which shows higher specific capacitances and superior rate capability than most reported MCo2S4 nanostructures with different morphologies as well as excellent cycling stability at high current densities due to the highly porous and robust NT-built network architecture as well as high conductivity, all allowing asymmetric solid-state supercapacitor with such MCo2S4 as positive electrode to achieve much superior energy density over those reported for similar devices and outstanding cycle ability.257