Achieving Ultrahigh Capacity with Self-assembled Ni(OH)2 Nanosheet-decorated Hierarchical Flower-like MnCo2O4.5 Nanoneedle as Advanced Electrode of Battery-Supercapacitor Hybrid Device

Self-assembled Ni(OH)2 nanosheet decorated hierarchical flower-like MnCo2O4.5 nanoneedles was synthesized via a cost-effective and facile hydrothermal strategy, aiming to realize high capacity as the advanced electrode of battery-supercapacitor hybrid (BSH) device. It is demonstrated that the as-synthesized hierarchical flower-like MnCo2O4.5@Ni(OH)2-nanosheet electrode exhibits high specific capacity of 318 mAh g−1 at current density of 3 A g−1 and still maintains a capacity of 263.5 mAh g−1 at higher current density of 20 A g−1, with an extremely long cycle lifespan of 87.7% capacity retention after 5000 cycles. Moreover, using the unique core-shell structure as the cathode and hollow Fe2O3 nanoparticles/reduced graphene oxide (rGO) as the anode, the BSH device delivers high energy density of 56.53 Wh kg−1 when the power density reaches 1.9 kW kg−1, and there is extraordinary good cycling stability with the capacity retention rate of 90.4% after 3000 cycles. It is believed that the superior properties or...