One-Dimensional Hybrid Nanostructured Anodes For Lithium-Ion Batteries: Synthesis, Characterization, And Application

Owing to their unique structural property, one-dimensional hybrid nanostructured anodes are expected to exhibit improved cyclic performance, higher capacities, and rate capability, and thus have been considered as one of the promising choices for lithium-ion batteries with long cycle life, high energy density, and power density.In the dissertation, we propose a facile template-engaged approach to obtain one-dimensional hybrid nanostructures for high-performance anodes of lithium-ion batteries. By using Sn nanorods, MWCNT, ZnO nanorods, and FeOOH nanorods as templates, a series of one-dimensional hybrid nanostructured anodes, such as SnO2-C hybrid nanotubes, MWCNT-SnO2-C coaxial nanocables, Sn-C hybrid nanorods, SnS2-SiO2 hybrid nanorods,α-Fe2O3-Ag hybrid nanorods, and Fe3O4-C hybrid nanroods, has been prepared through facile hydrothermal, solvothermal, layer-by-layer, and annealing methods. Owing to the unique structural property, the above-mentioned one-dimensional hybrid nanostructured anodes exhibit improved electrochemical performance. The main innovative results are displayed as follows:(1) By using Sn nanorods as templates, SnO2-C hybrid nanotubes have been prepared through a facile glucose hydrothermal carbonization approach. Compared to the pure SnO2 nanotube anode, the SnO2-C hybrid nanotube anode exhibits higher initial Coulombic efficiency, improved cyclic performance, and higher capacities. After 20 cycles, the discharge capacity is about 400 mAh/g.(2) By using MWCNT as templates, MWCNT-SnO2-C coaxial nanocables have been prepared through a facile layer-by-layer and subsequent glucose hydrothermal carbonization approach. Compared to the MWCNT-SnO2 coaxial nanocable anode, the MWCNT-SnO2-C coaxial nanocable anode exhibits higher initial Coulombic efficiency, excellent cyclic performance, and higher capacities. After 65 cycles, the discharge capacity is 462.5 mAh/g.(3) By using ZnO nanorods as templates, ZnO-SnO2 hybrid nanorods have been prepared through a facile layer-by-layer approach. Furthermore, by using ZnO nanorods as templates, SnO2-C hybrid nanotubes have been prepared through a facile layer-by-layer and subsequent glucose hydrothermal carbonization approach. The as-synthesized SnO2-C hybrid nanotube anode exhibits excellent cyclic performance and higher capacities. After 180 cycles, the discharge capacity is 410.1 mAh/g. (4) By using Sn nanorods as templates, Sn-C hybrid nanorods have been prepared through a facile glucose solvothermal carbonization approach. The solvothermal carbonization approach could effectively restrain the oxidation of Sn templates and yield Sn-C hybrid nanorods with high-purity. Compared to the pure Sn nanorod anode, the Sn-C hybrid nanorod anode exhibits higher initial Coulombic efficiency, improved cyclic performance, and higher capacities. After 20 cycles, the discharge capacity is 806.6 mAh/g.(5) By using Sn nanorods as templates, Sn-SiO2 hybrid nanorods have been prepared through a facile Stober method. Furthermore, by using Sn nanorods as templates and SiO2 as nanoreactors, layer-stacked SnS2-SiO2 and single-crystalline SnS-SiO2 hybrid nanorods have been prepared through a controllable sulfidation approach. SiO2 nanoreactors, which can effectively preserve the one-dimensional nanostructured morphology and single-crystalline feature of the Sn templates, play a critical role in the transformation from Sn nanorods to layer-stacked SnS2 and single-crystalline SnS nanorods. The as-synthesized SnS2-SiO2 hybrid nanorod anode exhibits excellent cyclic performance, higher capacities, and rate capability. After 25 cycles, the discharge capacity is 535.7 mAh/g.(6) By using FeOOH nanorods as templates,α-Fe2O3-Ag hybrid nanorods have been prepared through a facile layer-by-layer and subsequent annealing approach. Compared to the pureα-Fe2O3 nanorod anode, theα-Fe2O3-Ag hybrid nanorod anode exhibits improved cyclic performance and higher capacities. After 180 cycles, the discharge capacity is 549.8 mAh/g.(7) By using FeOOH nanorods as templates, Fe3O4-C andγ-Fe2O3-C hybrid nanorods have been prepared through a facile glucose hydrothermal carbonization approach. As efficient nanoreactors, carbon layer plays a critical role in the transformation from FeOOH nanorods to Fe3O4 andγ-Fe2O3 nanorods. The as-synthesized Fe3O4-C hybrid nanorod anode exhibits improved cyclic performance and higher capacities. After 40 cycles, the discharge capacity is 1056.2 mAh/g.