Na₃V₂(PO₄)₃ (NVP) has received extensive attention as a cathode material for Na-ion batteries (SIBs), but the low electronic conductivity limits its practical electrochemical performance. Elemental doping is an effective way to optimize the conductivity of NVP electrodes. Meanwhile, purifying vanadium requires removing Si, Cr, and Fe impurities that can be directly utilized as effective dopants at low cost. Herein, steered via first-principles calculation, we comprehensively investigate the structure, electronic properties, and Na ion diffusion behavior of Si, Cr, and Fe mono/multi-doped NVPs. The results show that Si doping effectively promotes the electrochemical reaction of V for higher electronic conductivity. Fe doping generates new electronic energy levels in the band gap of NVP, improving the electrode reaction and reducing the migration barrier of Na ions. Notably, Cr doping can greatly reduce the migration barrier of Na ions. Moreover, multi-element doping of Si, Cr, and Fe exhibits a synergistic effect of the individual doping elements. Our work can inspire searching for cost-effective multi-component cathode materials for NIBs.

Na ₃ V ₂ (PO ₄ ) ₃ (NVP)作为钠离子电池(SIB)的正极材料受到了广泛的关注，但较低的电子电导率限制了其实际电化学性能。元素掺杂是优化NVP电极电导率的有效方法。同时，提纯钒需要去除Si、Cr和Fe杂质，这些杂质可以直接作为有效掺杂剂以低成本利用。在此，通过第一性原理计算，我们全面研究了Si、Cr和Fe单/多掺杂NVP的结构、电子性质和Na离子扩散行为。结果表明，Si掺杂有效促进了V的电化学反应，获得了更高的电子电导率。Fe掺杂在NVP的带隙中产生新的电子能级，改善电极反应并降低Na离子的迁移势垒。值得注意的是，Cr掺杂可以大大降低Na离子的迁移势垒。此外，Si、Cr和Fe的多元素掺杂表现出各个掺杂元素的协同​​效应。我们的工作可以激发人们寻找具有成本效益的 NIB 多组分阴极材料。