To increase electrochemical performance of electrode material by attaching activated carbon particles on reduced graphene oxide sheets for supercapacitor

A convenient and scalable method is developed to attach the activated carbon particles (ACP) on the surface of reduced graphene oxide (rGO) sheets. The rGO sheets are beneficial for improving the electrochemical performance of the ACP, while ACP can effectively suppress the aggregation of the rGO sheets. Therefore, the symmetric supercapacitor based on this composite (RGO-ACP3) electrode delivers high specific capacitance of 116.88 F g(-1) at current density of 0.5 A g(-1) in 1 M H2SO4 electrolyte, and has a high capacitance retention of 97.85% after 8000 cycles at 5 A g(-1). More importantly, from the perspective of ACP, adding a portion of rGO to three low-cost ACP can increase the specific capacitance of the electrode material by 58.2%. It also provides high energy density of 11.90 W h kg(-1) at power density of 469.24 W kg(-1) in 1 M Na2SO4 electrolyte. In addition, the special capacitance contributed byrGO in the RGO-ACP15 reaches up to 541 F g(-1) at 0.5 A g(-1) in 1 M H2SO4. The results indicate that the synergistic effect betweenrGO sheets and ACP,makes RGO-ACP3 a promising low cost electrode material for high performance supercapacitors.