Gao Yun, Zhang Hang, Peng Jian, Wang Jinsong, Liu Xiaohao, Zhang Lingling, Xiao Yao, Li Li, Liu Yang, Qiao Yun, Wang Jiazhao, Chou Shulei
Institute for Carbon Neutralization Technology, College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, Zhejiang, 325035, P.R. China.
Wenzhou Key Laboratory of Sodium-Ion Batteries, Wenzhou University Technology Innovation Institute for Carbon Neutralization, Wenzhou, Zhejiang, 325035, China.
Adv Mater. 2025 Mar 19:e2417876. doi: 10.1002/adma.202417876.
High-performance, cost-effective cathodes are essential for grid-scale sodium-ion batteries (SIBs). Prussian blue analogs (PBAs) have shown great potential as SIB cathodes, but achieving both high capacity and long lifespan remains challenging. In this study, a series of low-cost ternary PBAs synthesized through structural regulation is presented to simultaneously achieve high capacity, stable cycling performance, and broad temperature adaptability. Among them, CuHCF-3 demonstrates a specific capacity of 132.4 mAh g with 73.3% capacity retention over 1000 cycles. In-depth analyses, using in situ techniques and density functional theory calculations, reveal a highly reversible three-phase transition (monoclinic ↔ cubic ↔ tetragonal) in NaCuMn[Fe(CN)]·□·2.14HO (CuHCF-3), which is driven by synergistic interactions between Mn and Cu. Mn enhances conductivity, increases the operating voltage, and introduces additional redox centers, while Cu mitigates the Jahn-Teller distortions associated with Mn and buffers volume changes during cycling. This structural synergy results in excellent temperature stability across a wide temperature range (-20 to 55 °C). 18650-type cylindrical cells based on CuHCF-3 with high loading density achieve 73.54% capacity retention over 850 cycles. This study offers valuable insights for designing durable, high-capacity electrode materials for SIB energy storage applications.
高性能、具有成本效益的阴极对于大规模钠离子电池（SIB）至关重要。普鲁士蓝类似物（PBA）作为SIB阴极已显示出巨大潜力，但要同时实现高容量和长寿命仍具有挑战性。在本研究中，通过结构调控合成了一系列低成本三元PBA，以同时实现高容量、稳定的循环性能和广泛的温度适应性。其中，CuHCF-3在1000次循环中表现出132.4 mAh g的比容量，容量保持率为73.3%。使用原位技术和密度泛函理论计算进行的深入分析表明，在NaCuMn[Fe(CN)]·□·2.14H₂O（CuHCF-3）中存在高度可逆的三相转变（单斜 ↔ 立方 ↔ 四方），这是由Mn和Cu之间的协同相互作用驱动的。Mn提高了导电性，增加了工作电压，并引入了额外的氧化还原中心，而Cu减轻了与Mn相关的 Jahn-Teller 畸变，并缓冲了循环过程中的体积变化。这种结构协同作用导致在很宽的温度范围（-20至55°C）内具有出色的温度稳定性。基于CuHCF-3的高负载密度18650型圆柱形电池在850次循环中实现了73.54%的容量保持率。本研究为设计用于SIB储能应用的耐用、高容量电极材料提供了有价值的见解。
