Fabrication Of Lithium Titanium Composite Oxide One-dimensional Nanostructures And Assembly Of Lithium Ion Battery

As one of the most promising candidates for high-rate lithium-ion batteries, spinel Li₄Ti₅O₁₂ has advantages of high charge-discharge potential plateau, zero-strain effect and good safety performance.Nevertheless, the slow kinetics of Li+ diffusion and low electronic conductivity limit its commercial application. Electrospinning has been proved to be one of the best methods to fabricate low-dimensional electrode materials owing to its simple operation, high efficiency and high reproducibility. Hence,Fabrication and improvement of the electrochemical performance of Li₄Ti₅O₁₂ one-dimensional nanostructured materials by electrospinning andfurther ion doping, controlling morphology and combining with other materials is an imperative subject of study.In this dissertation, Li₄Ti₅O₁₂/Li₂TiO₃,Li₄Ti₅O_11.7F_0.3 nanofibers and Li₄Ti₅O₁₂/Ag, Li₄Ti₅O₁₂/C nanobelts were synthesized by electrospinning combined with subsequent calcination. The morphology, structure and electrochemical performance of prepared samples were characterized by XRD, FE-SEM and electrochemical measurements. When the molar ratio of Li to Ti is 4.8 : 5, prepared Li₄Ti₅O₁₂/Li₂TiO₃ composite nanofibers exhibitperfect initial discharge capacity, better rate capabilityand super cycling stability. Methods of F- doping, Ag nanoparticle modification and carbon coating could also improve rate and cycling capacities of Li₄Ti₅O₁₂ by increasing electron conductivity. Some new results are obtained. These new findings have some guiding effects on the research of titanium-lithium battery.