O doped Tremella-shaped porous carbon for zinc-ion hybrid capacitors with long life and enhanced energy density

Despite many advantages of simultaneous combination supercapacitors and batteries as new type of energy storage devices, Zinc-ion hybrid capacitors (ZIHCs) suffer low energy density and poor cyclic stability, leading to increasing attention to the development of advanced carbon cathode materials as an effective strategy to overcome these limitations. Herein, this work reports a MIL-88-derived O doped Tremella-shaped porous carbon (O-T-PC) for ZIHCs, with capacity of 128 mAhg(-1) at 0.2 Ag-1, energy density of 77.6 Wh kg(-1) at 120 W kg(-1), and 1.54 % loss after 20,000 cycles. O-T-PC features with the following advantages: (i) rich O doping (5.1 at. %), contributing to pseudocapacitance and wettability; (ii) 651.6 m(2)g(-1) specific surface area, holding more ions and enabling shorter diffusion pathways; (iii) a rich graphite microstructure, enhancing electrical conductivity. These results demonstrate that O-T-PC has a great potential application propect, highlighting the significance of MOFsderived carbon materials to ZIHCs.