A hierarchical porous P-doped carbon electrode through hydrothermal carbonization of pomelo valves for high-performance supercapacitors

Porous carbon materials are synthesized from pomelo valves by the hydrothermal activation of H(3)PO(4) followed by simple carbonization. The as-synthesized hierarchically porous carbon electrode exhibits a high specific capacitance of 966.4 F g(−1) at 1 A g(−1) and an ultra-high stability of 95.6% even after 10 000 cycles. Moreover, the supercapacitor also demonstrates a maximum energy of 36.39 W h kg(−1) and a maximum power of 33.33 kW kg(−1) with an energy retention of 25.56 W h kg(−1), which paves the way for the development of high-performance, green supercapacitors for advanced energy storage systems.