Phosphorus in honeycomb-like carbon as a cathode boosting pseudocapacitive properties for Zn-ion storage

Zn-ion hybrid supercapacitors (ZSCs) are an advanced energy storage device displaying promising prospects with battery-type and capacitive electrodes. Unveiling the reaction paths of dopants in carbon cathode is essential for rationally improving deficient adsorption sites to match the high energy capacity of Zn anode. In this work, the P-doped honeycomb-like porous carbon with abundant micro/mesoporous channels is employed as a cathode for ZSCs. Phosphorus dopant could significantly enhance pseudo-capacitance by promoting the reaction of the oxygen functional groups and Zn ions, but does not participate in pseudo-capacitance reactions. The P-doped honeycomb-like porous carbon exhibits interconnected conductive network and abundant electroactive sites. The resulting ZSCs devices deliver an energy density of 129.3 Wh/kg at a power density of 1000 W/kg and 72.54 Wh/kg even at the high power density of 20000 W/kg as well as excelling cycling life over 10,000 cycles.