Stacked NiCoSe clusters decorated cross-shaped star-like MOF-derived NiCo2O4 heterojunction for hybrid supercapacitors

In view of the inadequate energy density of hybrid supercapacitors, developing high-performance heterojunction electrodes is a promising strategy to solve this problem. However, the precise design and synthesis of heterojunction structure remains a challenge. In this work, a stacked NiCoSe clusters decorated cross-shaped star-like MOF-derived NiCo₂O₄ heterojunction (MOF-NiCo₂O₄@NiCoSe) was well-defined designed. The abundant heterogeneous interfaces and unique structure provide a large reactive area and structural stability during charge and discharge, thus facilitating the electrochemical reaction kinetics and boosting the electrochemical properties of electrode. Impressively, the obtained MOF-NiCo₂O₄@NiCoSe exhibits an excellent specific capacitance of 1266 F g⁻¹ at 1 A g⁻¹, outstanding multiplicative performance (91.6 % at 10 A g⁻¹) and favorable cycling stability. In addition, the assembled device equipped with MOF-NiCo₂O₄@NiCoSe cathode exhibits uplifting electrochemical features in terms of a maximum energy density of 52.0 Wh kg⁻¹ at a power density of 800.0 W kg⁻¹ along with a high capacitance retention after 10,000 cycles.