Hierarchical NiCo2O4 nanostructured arrays decorated over the porous Ni/C as battery-type electrodes for supercapacitors

The rational construction of hierarchical electrode materials has always been an attractive strategic development in energy storage. In this paper, the porous Ni/C (NC) substrate, which is derived from Ni metal–organic frameworks (Ni-MOFs), is served as the conductive skeleton on Ni foam (NF) for supporting two different morphologies NiCo 2 O 4 nanostructure arrays (NiCo 2 O 4 /NC). The hierarchical layered nanomaterial utilizes   the porous NC substrate as “favorable skeleton” for electron transfer and is coupled to vertical well-organized NiCo 2 O 4 nanoarrays to improve specific capacitance of composites. Benefits from the advantages of hierarchical layered structure, the electrochemical properties of as-constructed NiCo 2 O 4 /NC with two different morphologies were better than those of pure NiCo 2 O 4 prepared under the same conditions. Moreover, the optimized NiCo 2 O 4 nanowires arrays on NC substrate (NiCo 2 O 4NWs /NC) electrode acquire prominent specific capacitance of 1945.9 F g −1 (270.3 mAh g −1 ) at 1 A g −1 and good rate performance. Additionally, the assembled asymmetric device by NiCo 2 O 4NWs /NC and carbon nanotube (CNT) displays a high energy density of 58.31 Wh kg −1 at a power density of 749.7 W kg −1 , as well as good cyclic stability. The remarkable properties manifest that the hierarchical NiCo 2 O 4NWs /NC electrode has a good prospect in electrochemical applications.