Rational design of NiMoO4@CoMoO4 core-shell microrods a promising binder-free positive electrode for high-performance asymmetric supercapacitor application

Designing novel materials with complex nanostructures is a successful method of enhancing their qualities in supercapacitor applications. Here, we have offered a rational design of NiMoO4@CoMoO4 core-shell microrods (CSMRs) on flexible stainless steel mesh (FSSM) by two steps of the reflux condensation process. The NiMoO4@CoMoO4 CSMRs electrode owns a high capacitance of 2126.3 F g−1 at a current density of 5 mA cm−2, apparently superior to the pristine NiMoO4 and CoMoO4 electrode. The NiMoO4@CoMoO4 CSMRs electrode has also demonstrated significant cycling abilities; 77.10% of the initial capacitance was retained after 5000 cycles at a current density of 40 mA cm−2. The asymmetric supercapacitors (ASCs), assembled with NiMoO4@CoMoO4 CSMRs as binder-free cathode and Fe3O4/C as an anode, display a high energy density of 116.23 W h kg−1 and a high power density of 1025.64 W kg−1. Furthermore, the NiMoO4@CoMoO4 CSMRs//Fe3O4/C ASCs cycle performance was studied at a current density of 20 mA cm−2, which shows 84.53% retention of the initial capacitance after 5000 cycles, indicating its remarkable long-term cycle stability. The rational design of NiMoO4@CoMoO4 CSMRs electrode has a high specific capacitance and strong cycling stability, making it a potential electrode material for high-performance supercapacitors.