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Industrial grade Ti O 2 and battery grade Li 2 CO 3 as raw material, based on high-temperature solid-state reaction method using a two-step sintering process preparation Li 4 Ti 5 O 12 anode material, and using XRD, SEM, programmable constant current charge-discharge test system by means of the morphology , crystal structure, electrochemical performance test characterization and modification based on this research, finding the optimal synthesis in order to prepare a more excellent performance Li 4 Ti 5 O 12 cathode material. First compare different carbon sources (glucose and soluble starch) Modification of the material properties. The results showed that the soluble starch as the carbon source, and by treating the resulting water bath modified sample modification works best. Then through the single factor experiment, the ratio of raw material were investigated, the second step sintering temperature and time on the properties of synthesized samples to determine the preparation of Li 4 Ti 5 O 12 / C material conditions: Li, Ti atomic ratio of 4.08:5 (2% excess of Lithium), step 600 ℃ sintering 4h, sintering at 800 ℃ step 6h, the sintering process is carried out under nitrogen. Further studies with different starch coating amount of the material properties, the results show that: with the increase in the amount of starch coating, residual carbon content in the sample increases, the particle size decreasing trend, but the second reunion intensified, conductivity increases, the tap density decreased discharge capacity first increased and then decreased. According to the theoretical carbon content 4wt% for starch coating modification optimum electrochemical performance of the sample: at room temperature 0.2C, 1C, 2C and 5C, the discharge capacity was 178.2,161,155.1 and 141.8mAh / g, 50 cycles capacity retention rate was 97.7%. Another Select Mg 2 , Al 3 and V 5 of dopant ions, in accordance with the preparation of pure phase Li 4 Ti 5 O 12 prepared by sintering regime, the experimental results showed that: three kinds of ion doping not alter Li 4 Ti 5 < / sub> O 12 crystal structure, but the electrochemical performance improved in varying degrees, by Mg 2 -doped best electrochemical performance of the samples, which may be Suitable ionic radius decreases because of the lattice distortion. Finally, the Mg 2 -doped and composite coated composite modified starch study, the experimentally determined carbon-coated modified sintering process for sample preparation and electrochemical test results showed that: composite modified slightly higher than the electrochemical properties of coated modified starch separate samples, indicating that the two methods can be modified in different ways together, the greater the degree of increase the electrochemical properties.
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