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A novel strategy for the synthesis of hierarchical porous carbons (HPCs) from resol by potassium acetate activation for advanced supercapacitor electrodes was reported. The resultant HPCs with a high specific surface area up to 1201 m 2 g −1 as a supercapacitor electrode exhibits a high specific capacitance of 226 F g −1 at 0.05 A g −1 . Besides, the electrode shows high rate capability with 62.4% retention from 0.05 to 20 A g −1 . Moreover, it demonstrates good cyclic stability, showing a high capacitance retention of 97.1% over 5000 charge-discharge cycles at 2.0 A g −1 . The facile, efficient and template-free synthesis strategy for novel 3D-HPCs may promote commercial application of HPCs in the fields of supercapacitors. [ABSTRACT FROM AUTHOR]

Graphene is considered as a promising electrode material for supercapacitors due to its large specific surface area, excellent electrical conductivity and so on. In this paper, few-layer graphene is prepared by self-propagating combustion reaction between CO and metal magnesium, using powder MgO as deposition template. Graphene with a high specific surface area of up to 928 m2 g−1 replicates the morphological feature of powder MgO. Raman spectroscopy analysis demonstrates that the graphene layer decreases when the dosage of MgO template is increased. The specific capacitance of as-prepared sample exhibits the highest specific capacitance of 222 F g−1 at the current density of 1 A g−1 in EMI [TFSI] electrolyte. The sample demonstrates a "double high" performance with high specific energy density and high specific power density. A high energy density of 76.3 Wh kg−1 can be achieved at a specific power density of 1.75 kW kg−1, and it can still remain 48.6 Wh kg−1 when the specific power density reaches a high level of 35 kW kg−1. • Self-propagating combustion reaction synthesis graphene. • Synthesis graphene from CO and Mg. • Synthesized graphene has good structural properties. • Excellent capacitive performances in the electrolyte of EMI [TFSI]. [ABSTRACT FROM AUTHOR]