| Today, researchers are facing to develop the low cost, efficient, eco-friendly, small size and light weight electrical energy storage devices as one of the major challenges they confronted, because of the problems of environmental pollution, the shortage of energy, the demand for efficient storage of other energy produced by solar, wind power, etc. and supporting the rapid development of portable electronic devices and electric vehicle.Lithium-ion batteries(LIBs) and supercapacitors become the research focuses, due to their own advantages. Since the high performance of LIBs and supercapacitors highly rely on the performance and rational design of electrode materials. NiO is a kind of pseudocapacitive material, which has attracted great attention because of the high theoretical specific capacitance, and V2O5, as one of cathode materials of LIBs, exhibits large energy density and great development potential. Both of them display some common advantages, such as low-cost and abundant, while the low electric conductivity, and poor cycling performance limit their application. It is reported that it can relieve the defects by application of nanoscale materials in electrodes. Therefore, numerous efforts are necessary to rational design and prepare high performance nano-materials in the application of electrochemical energy storage devices.In this paper, we aim at using simple methods to rational design and prepare nanostructured electrode materials with high performance for LIBs and supercapacitors.(1) The honeycomb-like mesoporous Ni O microspheres as promising cathode materials for supercapacitors have been achieved using a hydrothermal reaction, followed by an annealing process. The electrochemical tests demonstrate the highest specific capacitance of 1250 F g-1 at 1 A g-1. Even at 5 A g-1, a specific capacitance of 945 F g-1 with 88.4% retention after 3500 cycles was obtained. In addition, the 3D porous graphene(reduced graphene oxide, rGO) has been prepared as an anode material for supercapacitors, which displays a good capacitance performance of 302 F g-1 at 1 A g-1. An asymmetric supercapacitor has been successfully fabricated based on the honeycomb-like Ni O and rGO. The asymmetric supercapacitor achieves a remarkable performance with a specific capacitance of 74.4 F g-1, an energy density of 23.25 Wh kg-1, and a power density of 9.3 kW kg-1, which is able to light up a light-emitting diode.(2) In this study, various V2O5 hollow microspheres including yolk-shell structure, double-shell structure, tribble-shell structure and hierarchical hollow superstructures have been selectively prepared. The obtained hierarchical V2O5 hollow microspheres(HVHS) exhibit a high capacity of 123 mA h g-1 at 20 C(1C = 147 mA g-1) in the range of 2.5 to 4.0 V and 73.5 mA h g-1 can be reached after 3000 cycles. HVHS also display good cycling performance in the range of 2.0 to 4.0 V. Moreover, The V2O5//Li4Ti5O12 full-cell was successfully assembled, which exhibit an excellent performance of 139.5 mA h g-1 between 1.0 and 2.5 V at a current density of 147 mA g-1, and a capacity of 106 mA h g-1 was remained after 100 cycles, indicating the good cycling performance and promising application of the full cell. |
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