Microwave‐Assisted Synthesis of NiMn2O4 Grown on Nickel Foam as Electrode Material for High‐Performance Supercapacitors

Abstract The spinel NiMn 2 O 4 has been directly grown on 3D nickel foam by combining a simple microwave‐assisted hydrothermal with annealing process at different temperatures (350 °C to 650 °C), which can be used as a binder‐free electrode for high‐performance supercapacitors. The results indicate that the pure NiMn 2 O 4 can be obtained below 550 °C. The as‐prepared NiMn 2 O 4 at 450 °C has the largest specific capacitance of 802 F g −1 at 1 A g −1 and excellent cycle stability (61 % capacity retention after 5000 cycles at 10 A g −1 ) among all the obtained samples. This outstanding electrochemical performance may be attributed to its relatively large grain size, high specific surface area, and appropriate pore structure. This indicates that NiMn 2 O 4 grown on nickel foam shows great potential as an electrode material for supercapacitors.