CIC Energigune, Parque Tecnológico de Álava, C/Albert Einstein 48, 01510, Miñano, Vitoria, Álava, Spain.
Sci Rep. 2017 Jul 13;7(1):5350. doi: 10.1038/s41598-017-05629-x.
The search for Si-based anodes capable of undergoing low volume changes during electrochemical operation in rechargeable batteries is ample and active. Here we focus on crystalline Si, a recently discovered open-cage allotrope of silicon, to thoroughly investigate its electrochemical performance using density functional theory calculations. In particular, we examine the phase stability of Na Si along the whole composition range (0 ≤ x ≤ 4), volume and voltage changes during the (de)sodiation process, and sodium ion mobility. We show that Na Si forms a solid solution with minimal volume changes. Yet sodium diffusion is predicted to be insufficiently fast for facile kinetics of Na-ion intake. Considering these advantages and limitations, we discuss the potential usefulness of Si as anode material for Na-ion batteries.
寻找能够在可充电电池的电化学操作中经历低体积变化的 Si 基阳极是充足且活跃的。在这里，我们专注于晶体硅，一种最近发现的硅的开放式笼状同素异形体，使用密度泛函理论计算来彻底研究其电化学性能。特别是，我们研究了 NaxSi 在整个组成范围内（0≤x≤4）的相稳定性、（去）钠化过程中的体积和电压变化以及钠离子迁移率。我们表明，NaxSi 形成具有最小体积变化的固溶体。然而，钠离子扩散预计不够快，无法实现钠离子易于吸收的动力学。考虑到这些优点和局限性，我们讨论了 Si 作为钠离子电池阳极材料的潜在用途。
