Hydrogenation Synthesis of Blue TiO2 for High-Performance Lithium-Ion Batteries
Hydrogenation Synthesis of Blue TiO2 for High-Performance Lithium-Ion Batteries
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DOI：
10.1021/jp501819p
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发表时间：
2014-05-01
影响因子：
3.7
通讯作者：
Zhang, Shanqing
中科院分区：
文献类型：
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作者：
Qiu, Jingxia;Li, Sheng;Zhang, Shanqing
蓝色氢化金红石TiO2纳米粒子（蓝色TiO2）是通过强化加氢工艺（即高压和高温）处理白色金红石制备的。材料表征结果表明，与未经处理的白色TiO2相比，加氢过程导致晶胞体积增大，尺寸减小。电化学阻抗谱分析和密度泛函理论（DFT）理论能量计算表明，氢化过程不仅由于氢化过程中氧空位的形成而提高了电子导电性，而且由于氧空位和晶体位错的引入而显著增加了锂离子在晶格内的质量传输。由于氢化过程产生的这些特性，蓝色TiO2基锂离子电池（LIBs）比白色TiO2基锂离子电池具有更高的能量容量和更好的倍率性能。特别是，在0.1和5℃（1c = 336 rnag(-1)）下，蓝色金红石的放电容量分别保持在179.8和129.2 mAh g(-1)，而白色TiO2的放电容量分别仅为119.6和55.5 mAh g（-1）。
Blue hydrogenated rutile TiO2 nanoparticles (blue TiO2) are prepared by treating white rutile via an enhanced hydrogenation process (i.e., high pressure and temperature). The materials characterization results demonstrate that the hydrogenation process leads to the increase in the unit cell volume and decrease in the size compared with the untreated white TiO2. The electrochemical impedance spectra analyses and theoretical energy calculations using density functional theory (DFT) suggest that the hydrogenation process not only improves electronic conductivity due to the formation of oxygen vacancy in the hydrogenation process but also dramatically augments lithium-ion mass transport within the crystalline lattice due to the introduction of oxygen vacancy and crystalline dislocation. Because of these characteristics resulting from the hydrogenation process, the blue TiO2 based lithium ion batteries (LIBs) possess significantly higher energy capacity and better rate performance than the white TiO2 based LIBs. In particular, at the rate of 0.1 and 5 C (1 C = 336 rnAh g(-1)), the discharge capacities of the blue rutile are maintained at ca. 179.8 and 129.2 mAh g(-1,) while the capacities of the white TiO2 are just ca. 119.6 and 55.5 mAh g(-1) respectively.