Porous cobalt oxides/carbon foam hybrid materials for high supercapacitive performance

Abstract

Porous cobalt oxides/carbon foam hybrid materials (CoOx/C) was prepared by a solvothermal method. Owing to the heredity of the interconnected hierarchical porous structure from the carbon foam, the obtained CoOx/C composites had a larger specific surface area and a wider pore size distribution than CoOx, which facilitated the electron and ion transport. Benefiting from the synergistic contribution of CoOx nanoparticles and the porous carbon foam, CoOx/C possessed an excellent supercapacitive performance. When the mass percentage of the carbon foam was 10%, the CoOx/C composite (CoOx/C-10) exhibited a high specific capacity (115 mAh g−1 at 0.5 A g−1), an excellent rate capability (73 mAh g−1 at 10 A g−1) and a good cycling stability (86% after 6000 cycles at 1 A g−1). Meanwhile, an asymmetric device (CoOx/C-10//carbon foam) delivered a maximum energy density of 14 Wh kg−1 at a power density of 9056 W kg−1 as well as excellent cyclic lifetime (87% after 7000 cycles at 1 A g−1). In consideration of the excellent supercapacitive performance, the low cost and the facile preparation, CoOx/C-m is a promising electrode material for the supercapacitors.