Synthesis Of Different Shapes Of Metal Oxide Materials With Enhanced Lithium Storage Capabilities

Currently,rechargeable lithium-ion batteries,as a major device for electrical energy storage are considered as a critical enabler for next generation energy technology.Metal oxides have been attracted increasing attention as anode materials for Li-ion batteries owing to its advantages such as high energy density,reliable stability and long lifetimes.A series of metal oxides with different shapes(CuO and NiO)and Fe2O3-SnO2/graphene composites have been synthesized by physical and chemical methods and studied in the paper.The morphology,crystal phase,chemical compositions and electrochemical performance in lithium-ion batteries of these samples are tested and analyzed.The contents of this paper as follows:1.The self-assembled Fe2O3-SnO2/graphene(GNs)film a 2D hierarchical structure is successfully synthesized using Fe2O3-SnO2 and graphite as precursor by physical mixing?filtering and thermal reduction steps.The film can be used as working electrode directly without any binder or conductor.The Fe2O3-SnO2/GNs film exhibits excellent electrochemical performance as anode materials both in half and full cells.At 100 mA g-1,the Fe2O3-SnO2-GNs film delivers a capacity of 538 mAh g-1 after 90 cycles in half cell.For full cell,the film also exhibits a high capacity of 334 mAh g-1 at 100 mA g-1 after 30 cycles.The Fe2O3-SnO2/GNs exhibits much better lithium storage property than Fe2O3 and Fe2O3-SnO2 electrodes.2.The cubic CuO,octahedral CuO and dodecahedral CuO are successfully synthesized by water bath and high temperature calcined steps.The electrochemical and lithium-ion battery performance employing the shape controlled CuO materials is investigated,to explore the correlations between morphology and the electrochemical properties.At 100 mA g-1,cubic CuO,octahedral CuO and dodecahedral CuO deliver a capacity of 221,283 and 339 mAh g-1 after 100 cycles,respectively.The dodecahedral CuO electrode displays reversible capacities of 524,413,334,256 and 175 mAh g-1 at current densities of 0.1,0.25,0.5,1 and 2 A g-1,respectively.The dodecahedral CuO exhibits much better lithium storage property than cubic CuO and octahedral CuO electrodes.3.The hollow cubic NiO(HC-NiO)?hollow octahedral NiO(HO-NiO)and hollow dodecahedral NiO(HD-NiO)with uniform,well-defined and highly symmetric structure are successfully synthesized via the sacrificial-template method.When evaluated as anode materials for lithium-ion batteries,HD-NiO electrode exhibits a high specific capacity and excellent cycling performance compared with the HC-NiO and HO-NiO electrodes.At 100 mA g-1,HC-NiO,HO-NiO and HD-NiO deliver a capacity of 652,852 and 980 mAh g-1 after 100 cycles,respectively.The HD-NiO electrode displays reversible capacities of 1179,1026,944,825 and 730 mAh g-1 at current densities of 0.1,0.25,0.5,1 and 2 A g-1,respectively.HD-NiO exhibits excellent lithium storage property.