论文标题
ti/v阳离子 - 交换在na $ _2 $ _2 $ _3 $ o $ _7 $上对na-ion负极电极性能的影响：第一原理研究的见解
Influence of Ti/V Cation-Exchange in Na$_2$Ti$_3$O$_7$ on Na-Ion Negative Electrode Performance: an Insight from First-Principles Study
论文作者
论文摘要
坦烷酸钠\ ce {Na2ti3O7}（NTO）被视为一种高度有前途的阳极材料，对于Na-ion电池和电容器的电压非常低，但具有相对较低的特异性容量和电子电导率较差。在这里，我们报告了NTO及其钒修饰化合物的电化学性能的第一原理研究，\ ce {Na2ti2vo7}和\ ce {Na2tiv2O7}（NTVO），为通过TI/V c cations Exchanse增强其详细的工作机制提供了洞察力。我们的计算表明，当使用\ ce {nati_ {3- $ x $ x $ x $} v _ {$ x $ x $ = 1，2 $ = 1，2 $ = 1，2 $ x $ = 1，2 \ ce {v^{+5}}，以及低于3 \％的较低电压和较小的量膨胀率。借助Ti/V交换，我们获得了沿两个不同途径的NA离子迁移的激活能，但发现NTVO中电子传输的明显改善。
Sodium-titanate \ce{Na2Ti3O7} (NTO) is regarded as a highly promising anode material with a very low voltage for Na-ion batteries and capacitors, but suffered from relatively low specific capacity and poor electron conductivity. Here we report a first-principles study of electrochemical properties of NTO and its vanadium-modified compounds, \ce{Na2Ti2VO7} and \ce{Na2TiV2O7} (NTVO), offering an insight into their detailed working mechanism and an evidence of enhancing anode performance by Ti/V cation exchange. Our calculations reveal that the specific capacity can increase from 177 mAh g$^{-1}$ in NTO to over 280 mAh g$^{-1}$ in NTVO when using \ce{NaTi_{3-$x$}V_{$x$}O7} ($x$ = 1, 2) as a starting material for Na insertion due to higher oxidation state of \ce{V^{+5}}, together with lower voltages and small volume expansion rates below 3\%. With Ti/V exchange, we obtain slightly higher activation energies for Na ion migrations along the two different pathways, but find an obvious improvement of electronic transport in NTVO.
