Evaluation of undoped and M-doped TiO2, where M = Sn, Fe, Ni/Nb, Zr, V, and Mn, for lithium-ion battery applications prepared by the molten-salt method
Evaluation of undoped and M-doped TiO2, where M = Sn, Fe, Ni/Nb, Zr, V, and Mn, for lithium-ion battery applications prepared by the molten-salt method
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DOI：
10.1039/c5ra00206k
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发表时间：
2015-03
期刊：
影响因子：
3.9
通讯作者：
M. Reddy;N. Sharma;S. Adams;R. P. Rao;V. Peterson;B. Chowdari
中科院分区：
文献类型：
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作者：
M. Reddy;N. Sharma;S. Adams;R. P. Rao;V. Peterson;B. Chowdari
采用熔盐法合成了一系列含过渡金属的二氧化钛。发现一些过渡金属取代到TiO 2晶格中，例如（Ti 0.9Fe 0.1）O2、（Ti 0.9Zr 0.1）O2、（Ti 0.9V 0.1）O2和（Ti 0.9Mn 0.1）O2，而其它过渡金属形成为复合电极（除了相对较小的取代之外），即0.1SnO2- 0.9TiO 2和0.05NiO-0.1Nb2O5- 0.9TiO 2。虽然使用相同的合成条件，但不同的过渡金属产生不同的相。在这项工作中提出的电极相关的表面积和组合物（通过X射线光电子能谱，XPS），和电化学行为的比较研究。在取代的单相电极中，（Ti0.9Zr0.1）O2在1.0-2.6 V的电压范围内在第60次循环结束时表现出最好的可逆容量，为160 mA h g-1，从第2次到第60次循环的容量衰减为24%。在复合电极中，0.05NiO-0.1Nb2O5-0.9TiO2显示出最好的性能，其与纯TiO 2相当，但在延长的循环中具有较慢的容量衰减。性能最差的电极是（Ti0.9V0.1）O2，在1.0-2.6 V的电压范围内，在130 mA g-1的电流密度下，在70次循环结束时，可逆容量仅为1070 mA h g-1，并且从第2次循环到第70次循环，容量下降52%。复合材料0.1SnO2-0.9TiO2具有最高的不可逆容量损失。Zr取代到TiO 2中得到最好的电化学性能。
The molten-salt method was used to synthesize a series of transition-metal containing titanium dioxides. Some of the transition metals were found to substitute into the TiO2 lattice, such as (Ti0.9Fe0.1)O2, (Ti0.9Zr0.1)O2, (Ti0.9V0.1)O2, and (Ti0.9Mn0.1)O2, while others were formed as composite electrodes (in addition to relatively minor substitutions), namely 0.1SnO2–0.9TiO2 and 0.05NiO–0.1Nb2O5–0.9TiO2. Although identical synthesis-conditions were used the different transition metals yielded different phases. A comparative study of the electrodes relating surface area and composition (via X-ray photoelectron spectroscopy, XPS), and electrochemical behaviour is presented in this work. Among the substituted single phase electrodes, (Ti0.9Zr0.1)O2 exhibited the best reversible capacity of ∼160 mA h g−1, at the end of the 60th cycle in the voltage range 1.0–2.6 V, with a capacity fade of 24% from the 2nd to the 60th cycle. Among the composite electrodes, 0.05NiO–0.1Nb2O5–0.9TiO2 shows the best performance which is comparable to pure TiO2 but with a slower capacity-fade on extended cycling. The worst performing electrode is (Ti0.9V0.1)O2 with a reversible capacity of only ∼70 mA h g−1 at the end of 70 cycles with a current density of 130 mA g−1 in the voltage range 1.0–2.6 V and a capacity drop of 52% from the 2nd to the 70th cycle. The composite 0.1SnO2–0.9TiO2 features the highest irreversible capacity-loss. Zr-substitution into TiO2 gives the best electrochemical performance.