Prussian blue and its analogues are regarded as superior cathode materials for sodium ion batteries (SIBs) owing to low cost, open framework and large interstitial spaces for the insertion/extraction of sodium ion. Herein, a highly stable monoclinic sodium rich nickel hexacyanoferrate (II) nanocube (m-NiHCF) has been synthesized via a facile coprecipitation method with the aid of chelating agent and surfactant. It delivers a high specific capacity of 70.1 mAh g^-1 and maintains 97.1% capacity retention after 8000 cycles. Even at a high current density of 2000 mA g^-1, an impressive capacity of 53.2 mAh g^-1 is obtained. The fast kinetics of m-NiHCF is mainly benefited from the capacitive-controlled domination under the charge storage process. Meanwhile, ex-situ X-ray diffraction together with ex-situ X-ray photoelectron spectroscope and ex-situ Raman and ex-situ Fourier transform infrared analysis have revealed the reversible phase transition between monoclinic and cubic phases with the reaction of carbon coordinated Fe^II/Fe^III redox-active site during extraction and insertion of sodium ion in m-NiHCF framework. Furthermore, a high voltage aqueous SIB full cell assembled with NaTi₂(PO₄)₃@C anode achieves a high energy density of 86 Wh kg^-1 with capacity retention of 83% after 600 cycles, showing great prospects in the grid-scale energy storage application.

普鲁士蓝及其类似物由于成本低，开放的骨架以及用于插入/提取钠离子的较大间隙空间而被视为钠离子电池（SIB）的优质阴极材料。在此，借助于螯合剂和表面活性剂，通过简便的共沉淀法合成了高度稳定的单斜晶系富集六氰合铁酸镍（II）纳米晶（m-NiHCF）。它具有70.1 mAh g ^-1的高比容量，并在8000次循环后保持97.1％的容量保持率。即使在2000 mA g ^-1的高电流密度下，其惊人的容量也高达53.2 mAh g ^-1获得。m-NiHCF的快速动力学主要受益于电荷存储过程中电容控制的控制。同时，异位X射线衍射，异位X射线光电子能谱仪，异位拉曼光谱和异位傅里叶变换红外分析表明，单斜相和立方相之间可逆的相变是由碳配位的Fe反应引起的。在m-NiHCF骨架中提取和插入钠离子过程中的^II / Fe ^III氧化还原活性位点。此外，组装有NaTi ₂（PO ₄）₃ @C阳极的高压SIB水性全电池可实现86 Wh kg ^-1的高能量密度 600次循环后容量保持率达到83％，在电网规模的储能应用中显示出广阔的前景。