A strategy for constructing the compact carbon structure with high volumetric performance for supercapacitors from porous carbons

In this paper, we present an approach to construct the compact carbon structure with high volumetric capacitive performance by means of the porous carbon structural collapse and the introduction of oxygen-containing functional groups, which is exemplarily realized by oxidizing the porous titanium carbide-derived carbon (CDC) via a modified Hummers method. Electrochemical investigations demonstrate that the oxidized CDC exhibits simultaneously outstanding volumetric capacitance (216.6 F cm−3) and high gravimetric capacitance (228 F g−1) in 6 M KOH aqueous electrolyte, almost 23 and 16 times improvement in comparison to those of the pristine CDC (9.4 F cm−3 and 14 F g−1), respectively. Furthermore, the oxidized CDC also exhibits an excellent cycling stability (almost 92% specific capacitance being retained even after 10,000 cycles). The results of this work suggests that the strategy for constructing the compact carbon structure from the porous carbon by means of the structural collapse and the introduction of oxygen-containing functional groups will be promising for the development of the electrode material with high volumetric performance for supercapacitors.