Nitrogen and oxygen co-doped carbon networks with a mesopore-dominant hierarchical porosity for high energy and power density supercapacitors

• DOI: 10.1016/j.electacta.2017.03.218
• Publication Date: 2017-04-03T01:33:14Z
• Authors: Duanpeng He; Jin Niu; Meiling Dou; Jing Ji; Yaqin Huang; Feng Wang
• Keywords: Power density; Horizontal scan rate; Carbon fibers; Specific surface area

Abstract Nitrogen and oxygen co-doped hierarchical porous carbon (N,O-HPC) networks has been synthesized using cattle bones as precursors via pre-carbonization and carbonization combined with KOH activation. The effects of carbonization and activation temperature on the physiochemical and electrochemical performances of the N, O-HPCs were systematically studied. The N,O-HPC obtained at 850 °C (referred to as N,O-HPC-850) possesses a mesopore-dominant hierarchical porous network with a large specific surface area (2520 m2 g−1), a relatively high content of N (1.56%) and O (10.2%) and a good electrical conductivity (421.9 S m−1). As it is used as supercapacitor electrode material, N,O-HPC-850 exhibits a large specific capacity (444 F g−1 at a scan rate of 5 mV s−1 and 435 F g−1 at a current density of 0.1 A g−1, respectively) and good rate performance (252 F g−1 at a scan rate of 500 mV s−1 and 309 F g−1 at a current density of 20 A g−1, respectively) in 6 M KOH solution. Moreover, the assembled symmetric supercapacitor based on N,O-HPC-850 electrode delivers the energy density of 30.3 and 9.7 Wh kg−1 at the power density of 0.341 and 43.8 kW kg−1, respectively, and exhibits a good cycling stability with a capacitance retention of 97.5% after 20000 cycles in 1 M Na2SO4 solution.