| Instead of lithium metal, lithium-storage materials were adopted as negative electrode materials in lithium-ion batteries, the hidden insecurity and poor cyclic performance caused by the formation of lithium crystalline had been improved, and the high-voltage merit of lithium batteries was remained as well. At the same time, the lithium-ion batteries possessed other advantages such as high energy density, little weight, small volume, long cycle-life, little effect of memory and better environment benefits etc,so the lithium ion batteries had been developed rapidly during the past few years. This thesis concentrated on the tin-based oxide, spinel Li4Ti5O12, and their MWCNTs composite materials as anode material for lithium secondary batteries. The major work can be separated two parts.(一) In this section, the SnO and SnO2 nanophase anode materials were prepared by hydrothermal method, the different mole ratio of SnO/MWCNTs and SnO2/MWCNTs anode nanomaterials were prepared by hydrothermal method. The characteristic and electrochemical property of samples were investigated by powder X-ray diffraction (XRD), Scanning Electron Microscope (SEM) and electrochemical tests. The major contents as followed:(1) The SnO and SnO2 anode nanomaterials were prepared by hydrothermal method. The results of XRD showed that the Romarchite. Syn SnO and cassiterite SnO2 were synthesized by hydrothermal method. TEM showed that the microstucture of the sample was nanophase. the results of electrochemical tests showed that the cycliability of SnO and SnO2 which were added PEG-400 in preparing process were better than not added PEG-400.(2) The different mole ratio of SnO/MWCNTs nanocomposites anode materials were prepared by hydrothermal method. The results of XRD showed that the SnO/MWCNTs nanomaterials were successfully prepared by hydrothermal method. TEM photos showed that the SnO microstucture of the nanocomposites was nanorod and homogeneously dispersed on the MWCNTs surface. the results of electrochemical tests showed that MWCNTs could improve the cycliability of SnO.(3) The different mole ratio of SnO2/MWCNTs nanocomposites anode materials were prepared by hydrothermal method. The results of XRD showed that the SnO2/MWCNTs nanomaterials were successfully prepared by hydrothermal method. TEM images showed that the SnO2 microstucture of the nanocomposites were nanoparticles, most of particles were homogeneously dispersed on the MWCNTs surface and a few particles were in the hollow of MWCNTs. The results of electrochemical tests showed that the samples had excellent cycliability.(二) In this section, spinel Li4Ti5O12 has been synthesized by microwave synthesis method. The factors of the microwave power, radiation time, lithium source and reactant ratio which can effect on the final materials were investigated by means of XRD, FTIR, TEM, and electrochemical performances of Li4Ti5O12 were studied by electrochemical techniques. The major contents as followed:(1) The synthesis conditions of spinel Li4Ti5O12 were discussed, the discussed conditions were lithium source which were LiOH·H2O and Li2CO3 (Li excess 8%), microwave power which were 500W and 700W, radiation time which were 10min and 15min. The results of XRD and FTIR showed that the spinel Li4Ti5O12 could be synthesized when microwave power was 700W and radiation time was 15min, but a small amount of Li2TiO3 was found that may be caused by Li excess 8%. TEM showed that the microstucture of the sample were nanoparticles which diameter was about 30nm. The electrochemical performance of samples which were synthesized Li2CO3 as lithium source at 500W and 700W for 15min, the results of tests the samples have excellent cycliability.(2) The nonophase spinel Li4Ti5O12 was synthesized by microwave method. The condition of synthesis was that LiOH·H2O and Li2CO3 as lithium source at 700W for 15min. The results of XRD and FTIR showed that the nonophase spinel Li4Ti5O12 could be synthesized at 700W for 15min. TEM showed that the microstucture of the samples were nanoparticles which diameter was less than 30nm. the results of electrochemical tests showed that the samples had excellent cycliability.(3) The different mole ratio of Li4Ti5O12/MWCNTs nanocomposites anode materials were synthesized by microwave method. The nanocomposites were synthesized when Li2CO3 as lithium source at 700W for 15min.
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