Hierarchical NiCo 2 O 4 nanowalls composed of ultrathin nanosheets as electrode materials for supercapacitor and Li ion battery applications

Abstract In this work, NiCo 2 O 4 nanowalls composed of ultrathin nanosheets are fabricated successfully on Ni foam by a facile one-pot solvothermal method followed by thermolysis of the precursors. The as-prepared NiCo 2 O 4 products are evaluated as electrode materials for supercapacitors and lithium ion batteries. The results show high discharge capacitance of 925 mF/cm 2 at a current density of 5 mA/cm 2 , with remarkable cycling stability (about 24.2% loss after 6000 cycles) and excellent rate performance (71.5% capacitance retention with current density range from 1 mA/cm 2 to 20 mA/cm 2 ). In addition, Ni foam supported NiCo 2 O 4 nanowalls possess excellent discharge capacity of 1100 mAh/g as lithium ion battery anode at a current density of 100 mA/g. The excellent electrochemical performance of NiCo 2 O 4 nanowalls could be ascribed to the unique spatial structure composed of interconnected ultrathin nanosheets, which facilitates ion penetration and electron transportation, demonstrating their potential applications as electrode materials for high performance supercapacitors and lithium ion batteries.