Sodium-ion batteries are the primary candidate for a low-cost and resource-abundant alternative to lithium-ion batteries for large-scale electric storage applications. However, the development of sodium-ion batteries is hindered by the lack of suitable cathode materials that have sufficient specific energy density and cycle life. Here, we report layered NaVOPO₄ as a cathode material that exhibits high voltage (∼3.5 V versus Na/Na⁺), high discharge capacity (144 mAh g⁻¹ at 0.05 C), and remarkable cyclability with 67% capacity retention over 1,000 cycles. The excellent performances result from the high Na⁺ ion diffusion rate in the two-dimensional path and the reversible transformation behavior of (de)sodiation. Particularly, this layered structure and its synthetic procedure can be extended to other alkali-metal intercalation materials, leading to other metal-ion battery systems, which opens a new avenue for large-scale energy storage systems with the development of high-energy-density and long-life cathodes for electric storage applications.

钠离子电池是低成本和资源丰富的替代品的主要候选产品，可替代锂离子电池用于大规模电存储应用。然而，钠离子电池的发展由于缺乏合适的具有足够的比能量密度和循环寿命的阴极材料而受到阻碍。在这里，我们报道了作为正极材料的分层NaVOPO ₄，它表现出高电压（相对于Na / Na ⁺约为3.5 V ），高放电容量（在0.05 C下为144 mAh g ^-1）和出色的可循环性，在1000以上的时间内保持67％的容量周期。高的Na ⁺产生了出色的性能离子在二维路径中的扩散速率和（去）磺化的可逆转变行为。特别是，这种分层结构及其合成过程可以扩展到其他碱金属插层材料，从而导致其他金属离子电池系统，这随着高能量密度的发展为大规模储能系统开辟了一条新途径。以及用于电存储应用的长寿命阴极。