Preparation of nitrogen and oxygen co-doped porous carbon and study on the performance of Zn-ion hybrid supercapacitors

In this study, nitrogen-oxygen co-doped porous carbon materials with nano-sheet structure were successfully prepared by template method and chemical activation method using coal pitch with low cost and abundant sources as carbon precursor, urea as nitrogen source and template, and sodium hydroxide as activator. The porous carbon electrodes exhibit a maximum specific capacity of 255.5 mA·h/g at 0.05 A/g and a discharge specific capacity of 78 mA·h/g at 1 A/g. Moreover, the porous carbon electrodes deliver about 72.4% capacitance retention after 12000 cycles and a high energy density of 99.6 W·h/kg, showing great potential as cathode material. The nitrogen-oxygen co-doped porous carbon materials prepared from coal pitch display an excellent electrochemical performance as cathode material for zinc ion hybrid supercapacitors.