Anchoring sea urchin-like cobalt-nickel carbonate hydroxide on 3D carbon sponge for electrochemical energy storage

Newly developed functional materials for energy storage have attracted considerable attention because of rapidly increasing global energy consumption and environmental problems. In this study, a polycyclic aromatic hydrocarbon, perylene-3,4,9,10-tetracarboxylic dianhydride was used as a precursor to a three-dimensional (3D) carbon sponge (CS). Subsequently, the sea urchin-like cobalt-nickel carbonate hydroxide (NiCo–CH) was anchored on CS by a hydrothermal method , using urea as a stabilizer and alkali source. The obtained CS/NiCo–CH composite demonstrated excellent electrochemical performance with a specific capacitance of 643 F g −1 (1 A g −1 ) and outstanding cycle stability (84.2% of the initial capacitance was retained after 3000 charge/discharge cycles). In addition, an asymmetric supercapacitor constructed using CS/NiCo–CH and activated carbon as positive and negative electrodes, respectively, exhibited a high specific capacitance of 131.6 F g −1  at 1 A g −1 and high energy density of 38.4 Wh kg −1  at 724.1 W kg −1 . The proposed CS/NiCo–CH composite may be used for electrochemical energy storage.