N/P/O doped porous carbon materials for supercapacitor with high performance

Owing to the need for new-generation energy storage equipment and industrial application, the development of carbon electrode materials with comprehensive electrochemical performances and convenient production processes has become a top priority. In this study, N/P/O doped carbon materials are prepared using a simple one-step method with 4-(2,4,6-tricarboxylphenyl)-2,2′:6′,2″-terpyridine (TT) as a raw material. Owing to the doping of many heteroatoms, particularly phosphorus atoms, the optimized TT(Zn/P)-700 exhibits a large specific surface area (2164.7 cm2/g), proper pore distribution from micropore to macropore, and high degree of graphitization. These structural and morphological features ensure excellent comprehensive capacitance performance, such as a high specific capacitance (366.25 F/g at 0.5 A/g), and high specific energy (73.25 Wh/kg at 300 W/kg). In addition, the specific capacitance of the symmetric supercapacitor assembled with TT(Zn/P)-700 electrode reaches 143.3 and 121.7 F/g at specific currents of 0.5 and 10 A/g, respectively. The specific current is increased 20 times, and the capacitance retention rate reaches 84.9%, improving the rate performance. When the specific power increases to 150 and 3000 W/kg, the specific energy reaches 7.17 and 6.08 Wh/kg, respectively. After 5000 charge/discharge cycles, the capacitance retention rate is 92.7%. These high-performance N/P/O-doped carbon electrode materials demonstrate great potential in industrial applications and new-generation energy storage equipment.