Mesoporous NiCo2O4 nanosheets with enhance sodium ion storage properties

Two kinds of the NiCo2O4 nanosheets constructed by interconnected nanoparticles with different microstructures, including ultrathin NiCo2O4 nanosheets (NiCo2O4-UNSs) and common NiCo2O4 nanosheets (NiCo2O4-NSs), were controllably synthesized by a facile method. The structure and morphology of the NiCo2O4 nanosheets were analyzed and characterized by XRD, SEM and TEM. NiCo2O4-UNSs possess a large surface area (119 m(2) g(-1)) and narrow pore distribution (around 5 nm). Subsequently, the Na-ion storage properties of such NiCo2O4 nanosheets were investigated by sodium half-cells. The ultrathin NiCo2O4 nanosheets (NiCo2O4-NSs) exhibit much improved performance than that of NiCo2O4-NSs with a high reversible capacity of 690.4 mA h g(-1) at 100 mAg(-1) and 141.8 mA h g(-1) at the current density of 1000 mA g(-1) in the voltage window of 0.01-2.5 V. Furthermore, a reversible capacity of about 203.7 mA h g(-1) can be remained after 50 cycles at 200 mAg(-1). (C) 2015 Elsevier B.V. All rights reserved.