| Summary: | 碩士 === 大同大學 === 化學工程學系(所) === 103 === In this study, the samples of Li4Ti5O12 with or without aluminum doping / carbon coating (designated as LTO, LTO/C, LTAO and LTAO/C) were synthesized via a facile sol-gel method, in which citric acid was used as carbon source and chelating agent. The structure, surface morphology and composition were characterized by X-ray diffraction, scanning electronic microscopy, Raman scattering spectroscopy, transmission electron microscopy and X-ray photoelectron spectroscopy. The electrochemical properties of the samples were examined by using the charge/discharge tests, and electrochemical impedance spectroscopy. The results show that LTAO/C composite electrode demonstrated the best electrochemical performance among all samples. For instance, its reversible discharge capacity can achieve up to 174.1, 166.3, 158 and 145.2 mAh g-1 at current density of 1C, 5C, 10C and 20C, respectively. Aluminum doping to carbon coating alone LTO samples (LTAO and LTO/C) can indeed improve the electrochemical properties of the LTO by enhancing the lithium diffusion and electronic conductivity of the electrode. As a result, both of the aluminum doping and carbon coating for LTOs revealed improved C-rate capability. As a result, the LTAO/C electrode exhibited great potential as a high-performance anode material for lithium-ion batteries.
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