| The worldwide popularity of various portable electronics leads to a wider application of lithium ion batteries. In recent years, with the increasing attention on the Electric Vehicle (EV) and Hybrid Electric Vehicle (HEV), the requirement on the performance of lithium battery becomes higher and higher, for instance, the requirement of high capacity, high output power, good cycling stability and high safety performance, etc. As the lithium ion battery anode material, TiO2 is worth of further investigation, for its structural stability, good cycle stability and high discharge voltage plateau during charge/discharge cycles. TiO2 nanotubes anode materials can fully contact with the electrolyte and effectively shorten the diffusion distance of lithium ion with the large specific surface area. So, researches on the application of TiO2 in lithium battery anode materials are widely carried out. However, the theoretical capacity of TiO2 nanotube electrode is 335mAh/g, similar to the traditional graphite electrode.In order to improve the capacity to meet the increasing requirement, many methods are proposed. The theoretical specific capacity of some metallic oxides, such as CuO, Fe2O3 and ZnO, is very high, but the volume effect of these materials is large in the cycle process, which will damage the material structure and weaken poor cycle performance. This paper selects the three kinds of metallic oxides mentioned above and compounds each oxide with through-hole TiO2 nanotube array(TiO2 NTs), and then TiO2 NTs with oxide are obtained and assembled into lithium battery, which can make full use of the synergistic effect of large capacity of metal oxide and stability of TiO2 nanotube structure. In this way, the electrochemical performance gets improved. The main conteNTs of this paper includes:(1)By using anodic oxidation, electro-deposition and anneal, CuO/TiO2 NTs under different deposition time are obtained. As the anode materials for lithium battery, CuO/TiO2 NTs possess better electrochemical performance, when the electrodeposition time is 5 minutes and 10 minutes. The first discharge capacity of this composite electrode is 343mAh/g and the reversible capacity is 182mAh/g after 30 cycles. This result indicates that the capacity of lithium battery improves significantly and the cycle stability is better. Tubular TiO2 array network can limit the volume effect of CuO nanoscale particles and CuO nanowires to a certain extent in the process of discharge/charge cycles and improve the reversibility and cycle stability of composite material.(2)By taking three steps mentioned above, Fe2O3/TiO2 NTs under different deposition time are obtained. As the anode materials for lithium battery, the first discharge capacity of this composite electrode is 384mAh/g and the charge capacity is 205mAh/g. The coulombic efficiency is 53%. TiO2 NTs with Fe2O3 can form SEI film in the discharge/charge process. A large number of lithium ions are consumed in the process of film formation, which leads to a relatively large irreversible capacity loss. At the same time, the resistance of part SEI film increases. Although the first discharge capacity of lithium battery gets improved, the cycle performance and conductive performance get descended respectively.(3)ZnO/TiO2 NTs under different deposition time are also obtained, by taking the same three steps mentioned above. The improvement of adding ZnO into TiO2 NTs is very limited. The performance of ZnO/TiO2 NTs battery prepared under the deposition voltage of 3V is better than that prepared under 5V. But the charge capacity is higher than TiO2 NTs electrode at the first 5 cycles, after which it continues falling. The performance is a mixed result of the two aspects of the morphology of electrode materials and SEI film. |
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