Hierarchical Heterostructures of NiCo2O4@XMoO4 (X = Ni, Co) as an Electrode Material for High-Performance Supercapacitors

Hierarchical heterostructures of NiCo2O4@XMoO4 ( X = Ni, Co) were developed as an electrode material for supercapacitor with improved pseudocapacitive performance. Within these hierarchical heterostructures, the mesoporous NiCo2O4 nanosheet arrays directly grown on the Ni foam can not only act as an excellent pseudocapacitive material but also serve as a hierarchical scaffold for growing NiMoO4 or CoMoO4 electroactive materials (nanosheets). The electrode made of NiCo2O4@XMoO4 presented a highest areal capacitance of 3.74 F/cm(2) at 2 mA/cm(2), which was much higher than the electrodes made of NiCo2O4@XMoO4 (2.452 F/cm(2)) and NiCo2O4 (0.456 F/cm(2)), respectively. Meanwhile, the NiCo2O4@XMoO4 electrode exhibited good rate capability. It suggested the potential of the hierarchical heterostructures of NiCo2O4@XMoO4 as an electrode material in supercapacitors.