Facile synthesis of three-dimensional interconnected porous carbon derived from potassium alginate for high performance supercapacitor

Porous carbon obtained by the conventional two-step way (chemical activation after carbonization) is confronted with the problems of long time-consuming, high cost and undeveloped macropore structure. Herein, for the first time, we report a facile and scalable way for the construction of three-dimensional (3D) interconnected porous carbons (IPC) originated from potassium alginate by a self-activation process. Owing to the high surface area, 3D interconnected ion diffusion channel and massive oxygen functional groups, the optimized IPC-800 electrode displays a high specific capacity of 279 F g−1 at 1 A g−1, superior rate capability (200 F g−1 at 50 A g−1) and excellent electrochemical stability with 96.6% capacitance retention after 10000 cycles in 6 M KOH aqueous electrolyte. Moreover, the assembled IPC-800//IPC-800 symmetric supercapacitor shows an energy density of 16.9 Wh kg−1 and good electrochemical stability in 1 M Na2SO4 aqueous electrolyte. These exciting results indicate a facile, economical and scalable method for the synthesis of porous carbon materials for high performance supercapacitors. •Three dimensional interconnected porous carbons (IPC) originated from potassium alginate by a self-activation process.•The IPC delivers high gravimetric capacitances and excellent electrochemical stability.•The as-assembled symmetric supercapacitor delivers high energy density and excellent electrochemical stability.