We demonstrate a simple hydrothermal approach to obtain a carbon-based NiCo2O4 material for use in supercapacitors. In this process, filter paper was submerged in a NiCo2O4 precursor solution, and the final product was obtained after calcination in an Ar2 atmosphere. The hydroxyl group-containing cellulose in the filter paper facilitates the formation of 3D structures, which not only improve the electrical conductivity but also provide fast electron and ion transport after calcination at high temperature, thus improving the electrochemical performance. An asymmetric supercapacitor has been assembled by using NCO/C-2 and activated carbon as the positive and negative electrodes. The NCO/C-2//AC ASC device exhibits a maximum energy density of 20.87 Wh kg-1 at a power density of 374.6 W kg-1 and a maximum power density of 7.48 kW kg-1 at an energy density of 11.43 Wh kg-1.