Cobalt And Nitrogen Atoms Co-doped Porous Carbon For Advanced Electrical Double-layer Capacitors

Electrical double-layer capacitors are widely concerned for their high power density, long cycle life and high cycling efficiency.However,their wide application is limited by their low energy density.In this thesis,we propose a simple and environmentally friendly method to synthesize cobalt and nitrogen atoms co-doped porous carbon material?Co AT-NC?.Cobalt atoms connected with primarily pyridinic nitrogen atoms can uniformly dispersed in the amorphous carbon matrix,which is benefit for improving the wettability,electrical conductivity and density of states of the carbon material.Therefore,an enhanced performance is expected when Co AT-NC is served as electrode in a supercapacitor device.Co AT-NC displays a good gravimetric capacitance of 160 F g^-1 at0.5 A g^-1 combing with outstanding capacitance retention of 90%(144 F·g^-1)at an extremely high current density of 100 A g^-1 in acid electrolyte,and the specific capacitance can still maintain 96.3%of the initial capacitance after 6,500 cycles at 2 A·g^-1.Furthermore,a good energy density of 30 Wh kg^-1 can be obtained in the organic electrolyte,which is higher than that of commercial supercapacitors(10–20 Wh·kg^-1).These excellent rate capability and cyclic stability make the metallic atom doped carbon material?Co AT-NC?become a promising electrical double-layer capacitor electrode material.