Construction of hollow core-shell Co9S8 dodecahedron with dual-carbon confinement for sodium-ion hybrid capacitors

As one of the promising alternatives for high energy-power supplying system, sodium ion hybrid capacitors (SIHCs) still remain a challenge towards seeking robust anode materials for hosting larger Na + . Cobalt sulfides are expected to be desired anode material due to its high capacity and superior thermal stability, but the application is hindered by the huge volume change. Herein, a hollow core-shell architectural Co 9 S 8 dodecahedron with dual‑carbon confinement (Co 9 S 8 /C@CNPS) is fabricated by controllable pyrolysis of ZIF-67 assisted with polymer. The unique structural features of small particle size, ample surface heteroatom doping, hollow architecture and dual‑carbon confinement can effectively shorten ions/electron transport path, offer abundant active sites as well as relax volume strain upon cycling. Consequently, the fast kinetic behavior and robust host structure endow Co 9 S 8 /C@CNPS with impressive performance for Na + storage. By integrating Co 9 S 8 /C@CNPS anode with a tobacco-derived biomass porous carbon (DTPC) cathode, the as-assembled SIHC demonstrates a high energy density of 96.5 W h kg −1 , high power supplying of 21 kW kg −1 and a long cycling stability with high capacity retention of 97.98 % after 10,000 cycles at 1 A g −1 . This work may shed light on the role of the structural engineering in electrode materials design.