Kulish Vadym V, Koch Daniel, Manzhos Sergei
Department of Mechanical Engineering, Faculty of Engineering, National University of Singapore, Block EA #07-08, 9 Engineering Drive 1, Singapore 117576.
Phys Chem Chem Phys. 2017 Aug 23;19(33):22538-22545. doi: 10.1039/c7cp04360k.
Vanadium oxides are among the most promising materials that can be used as electrodes in rechargeable metal-ion batteries. In this work, we systematically investigate thermodynamic, electronic, and kinetic properties associated with the insertion of Li, Mg and Al atoms into rutile VO. Using first-principles calculations, we systematically study the structural evolution and voltage curves of LiVO, MgVO and AlVO (0 < x < 1) compounds. The calculated lithium intercalation voltage starts at 3.50 V for single-atom insertion and decreases to 2.23 V for full lithiation, to the LiVO compound, which agrees well with the experimental results. The Mg insertion features a plateau about 1.6 V up to MgVO and then another plateau-like region at around 0.5 V up to MgVO. The predicted voltage curve for Al insertion starts at 1.98 V, followed by two plateaus at 1.48 V and 1.17 V. The diffusion barrier of Li, Mg and Al in the tunnel structure of VO is 0.06, 0.33 and 0.50 eV, respectively. The demonstrated excellent Li, Mg and Al mobility, high structural stability and high specific capacity suggest promising potential of rutile VO electrodes especially for multivalent batteries.
钒氧化物是最有前景的可用于可充电金属离子电池电极的材料之一。在这项工作中，我们系统地研究了与锂、镁和铝原子插入金红石型VO₂相关的热力学、电子和动力学性质。使用第一性原理计算，我们系统地研究了LiVO₂、MgVO₂和AlVO₂（0 < x < 1）化合物的结构演变和电压曲线。计算得出的锂嵌入电压对于单原子插入起始于3.50 V，对于完全锂化至LiVO₂化合物则降至2.23 V，这与实验结果吻合良好。镁的插入在达到MgVO₂之前有一个约1.6 V的平台，然后在达到MgVO₂时在约0.5 V处有另一个类似平台的区域。预测的铝插入电压曲线起始于1.98 V，随后在1.48 V和1.17 V处有两个平台。锂、镁和铝在VO₂隧道结构中的扩散势垒分别为0.06、0.33和0.50 eV。所展示的锂、镁和铝的优异迁移率、高结构稳定性和高比容量表明金红石型VO₂电极具有广阔的潜力，特别是对于多价电池。
