Iron-based hexacyanoferrate (Fe-HCF) are promising cathode materials for sodium-ion batteries (SIBs) due to their unique open-channel structure that facilitates fast ion transport and framework stability. However, practical implementation of SIBs has been hindered by low initial Coulombic efficiency (ICE), poor rate performance, and short lifespan. Herein, we report a coordination engineering to synthesize sodium-rich Fe-HCF as cathodes for SIBs through a uniquely designed 10-kg-scale chemical reactor. Our study systematically investigated the relationship between coordination surroundings and the electrochemical behavior. Building on this understanding, the cathode delivered a reversible capacity of 99.3 mAh g −1 at 5 C (1 C = 100 mA g −1 ), exceptional rate capability (51 mAh g −1 even at 100 C), long lifespan (over 15,000 times at 50 C), and a high ICE of 92.7%. A full cell comprising the Fe-HCF cathode and hard carbon (HC) anode exhibited an impressive cyclic stability with a high-capacity retention rate of 98.3% over 1,000 cycles. Meanwhile, this material can be readily scaled to the practical levels of yield. The findings underscore the potential of Fe-HCF as cathodes for SIBs and highlight the significance of controlling nucleation and morphology through coordination engineering for a sustainable energy storage system.

中文翻译：

---

铁基六氰基铁酸盐作为钠离子电池高稳定性正极的配位工程


铁基六氰基铁酸盐（Fe-HCF）由于其独特的开放通道结构有利于快速离子传输和框架稳定性，是有前途的钠离子电池（SIB）正极材料。然而，SIB 的实际应用受到初始库仑效率 (ICE) 低、倍率性能差和寿命短的阻碍。在此，我们报告了一种协调工程，通过独特设计的 10 公斤级化学反应器合成富钠 Fe-HCF 作为 SIB 的阴极。我们的研究系统地研究了配位环境与电化学行为之间的关系。基于这一理解，正极在 5 C (1 C = 100 mA g −1 ) 下具有 99.3 mAh g −1 的可逆容量、出色的倍率性能（即使在 100 C 下也有 51 mAh g −1 ）、长寿命（超过50℃下15,000次），ICE高达92.7%。由 Fe-HCF 阴极和硬碳 (HC) 阳极组成的全电池表现出令人印象深刻的循环稳定性，在 1,000 次循环中容量保持率高达 98.3%。同时，这种材料可以很容易地扩展到实际的产量水平。研究结果强调了 Fe-HCF 作为 SIB 阴极的潜力，并强调了通过协调工程控制成核和形态对可持续储能系统的重要性。