One Dimension Co₃O₄/NiO Composite And Sesame-like Porous SnO₂:Preparation And Electrochemical Performances Study

Now, new energy storage devices have attracted much attention due to environment pollution and energy depletion. The supercapacitor and the lithium-ion batteries become a promising candidate for their advantages including high power density, high energy density, fast charge and discharge, and environment-friendliness. The specific capacities of supercapacitors and lithium-ion batteries are strongly related to the electrode materials. Currently, the most popular material for supercapacitors and lithium-ion batteries is graphite. Unfortunately, the theoretical capacity for graphite is only 372 mAh g-1, hardly meeting the demand of practical application.(1) Hence, the development of new battery anode materials with high specific capacity is of significance to supercapacitors and Li+ batterery for practical application. The main results of this paper is as follows:Three dimensional sesame-like porous SnO2 were facilely prepared through annealing metal-organic framework precursors under an air atmosphere at 450℃, which were fabricated by a simple refluxed method. The porous rutile SnO2 was investigated as a lithium-ion battery anode. The porous structure of rutile SnO2 enforces Li+ diffusion and helps to buffer the volumetric variation during Galvanostatic charge and discharge measurements. The results show that the 3D sesame-like SnO2 exhibit excellent cycling stability. The specific capacitance still remains 401 mA h g-1 after 100 cycles, which is nearly 1.5 times higher than that of the noneporous SnO2.Our synthetic strategy could be useful to design high-performance electrodes for Lithium ion batteries.(2) One dimensional (1-D) wire-like NiO/Co3O4 composites were facilely prepared through annealing 1-D Ni/Co alloys, which was fabricated by a simple magnetic field-assisted hydrothermal method. Galvanostatic charge and discharge measurements reveal that the 1-D NiO/Co3O4 composites display excellent cycling stability. The specific capacitance still remains 221 F g-1 after 1500 cycles, which is nearly 1.5 times higher than that of the irregular NiO/Co3O4 spherical composite particles. And thus, this facile synthetic strategy could be useful to design high-performance electrode for supercapacitors.