Fabrication of hollow bamboo-shaped NiCo2O4 with controllable shell morphologies for high performance hybrid supercapacitors

Hollow nanostructures of metal oxides have been demonstrated as promising potential materials for variety applications such as supercapacitors. In this work, a simple sacrificial template method is developed to fabricate hollow bamboo-shaped NiCo2O4 (H-NiCo2O4) with ultrathin nanosheets. More importantly, the choice of the alkaline precipitant has great influence on the morphologies of the nanosheets. As expected, the H-NiCo2O4 based single electrode displays a high specific capacity of 680.1C g(-1) at the current density of 1 A g(-1). And excellent rate capability of the materials can be verified at the current density of 10 A g(-1), the specific capacity can reach to 618 C g(-1) . A remarkable cycling ability of the H-NiCo2O4 is manifested with stable capacity retention of 99.7% after 5000 times cycles at the current density of 10 A g(-1). In addition, the hybrid supercapacitor is assembled using the prepared hollow NiCo2O4 (H-NiCo2O4) as positive electrode and nitrogen-doped mesoporous carbon (NMC) as negative electrode, which displays high energy density of 59.82 Wh kg(-1) and power density of 8 kW kg(-1). This work can provide a potential hollow structure positive material for high performance supercapacitors. (C) 2020 Elsevier B.V. All rights reserved.