| Recently, the battery industry, as an important section of energy industry, is paid more attention and developed rapidly owing to the energy crisis and environmental pollution. Lithium ion battery is the focus of worldwide R&D because of their good safety, the flexibility of shape designing, high capacity, and good cycle life.In this work, anode materials, gel polymer membranes, additives for Li-ion battery, and the manufacture procedures etc have been investigated, aiming to improve the properties and performances of Li-ion batteries. The main results and conclusions are summarized as follows:1. In order to understand the mechanism of lithium ion intercalation/de-intercalation into carbon materials clearly, three-dimensional ordered bicontinuous mesoporous carbon (C-FDU-5) was synthesized by using mesoporous silica (FDU-5) as a hard template from an impregnation procedure. Electrochemical properties of the materials were studied for the first time as an anode material in lithium ion batteries.Thecubic mesoporous carbon materials, negatively replicated from mesoporous silica FDU-5 templates, presents the somewhat graphitic structure of the materials with I4132 space group. Meanwhile, the mesostructured carbon C-FDU-5 has a uniformed pore size of 7.4 nm, a high BET surface of 750 m2/g. No phenomenon of organic electrolyte decomposition was observed in the first negatively going process of voltammogram while continuous decrease the potential in charge process. It was suggested that the formation of solid state interface (SEI) on the surface of carbon materials and the process of lithium intercalation into the material occur simultaneously in the first cathodic process. There are two peaks corresponding to the lithium ion intercalation and de-intercalation in the first voltammogram respectively. The reversible capacity is higher than that of carbon nanotube and lower than that of graphitic carbon. It suggests that the doping of lithium into the available micro-pores and edge of part crystallized carbon is partly reversible owing to the special electronic structure of mesocarbon. These results also reveal that lithium ions can't be accommodated inside the similar structure of carbon nanotube. Moreover, the high first irreversible capacity can be attributed to SEI formation and Li side reaction. It was found that mesoporous carbon presented the capability for high rate discharge.The data of EIS suggest that the products of side reaction form a porous organic salt layer on the surface of carbon materials when the potential is above 2.0 V. Duringthe decrease of potential, the electrolyte begins to decompose on the surface of the carbons and gradually forms a SEI layer. Finally, a compact and dense porous layer is formed due to the distribution of decomposed products in the porous structure. Both constant resistance and Li+ diffusion coefficient were measured when the potential was lower than the critical potential. The electrochemical chracteristics can be attributed to the special 3 D porous structure of materials with thin "walls" and a large BET surface area (749 m2 /g), which can improve the contact between organic electrolyte and carbon materials. It is quite different from common carbon materials in which lithium ion intercalation reaction happened only after the formation of SEI layer. 2. In order to exploit new negative materials with high capacity, tin dioxide nanomaterials were synthesized through the self-assembly of inorganic tin precursor (SnCl2 and SnCl4 ) using triblock copolymer P123 as template. XRD patterns reveal a good crystalline tetragonal (p42/mnm) structure of the samples. TEM images clearly present that the sizes of nanoparticles distributed very uniformly. The average size of tin dioxide particles is about 15 nm, completely consistent with the result calculated from Scherrer diffraction formula. HR TEM image of sample shows that the tin dioxide particle is in single crystal structure with the interplanar distance of 2.83 ?, which is in good agreement with the value of...
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