Han Lijie, Ling Ying, Gong Wenbin, Xiao Dewei, Luo Jie, Zhang Qichong
Key Laboratory of Multifunctional Nanomaterials and Smart Systems, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, 215123, China.
School of Physics and Energy, Xuzhou University of Technology, Xuzhou, 221018, China.
Angew Chem Int Ed Engl. 2025 Jul 28;64(31):e202507427. doi: 10.1002/anie.202507427. Epub 2025 May 30.
Copper hexacyanoferrate (CuHCF) with 3D channels and high discharge plateau is widely recognized as a highly promising cathode material for ammonium-ion (NH ) storage. However, the practical application of CuHCF has faced challenges due to limited capacity and structural instability, primarily arising from single active site and serious Jahn-Teller distortions. Herein, an innovative in-situ dynamic compensation strategy is reported to prepare Zn-doping dual-active-site CuHCF (ZnCuHCF) as high-energy and ultrastable cathode materials for NH storage. Zn doping induces fission of Cu e orbitals, causing lattice to aberrate and reach stable state, while during NH intercalation process, changes mainly in Fe t electronic orbitals help maintain stability of ZnCuHCF structure. Consequently, ZnCuHCF in 23 m NHOTf + 0.5 m Zn(OTf) aqueous electrolyte exhibits high discharge potential of 0.94 V, high capacity of 121.7 mAh g at 1 A g and impressive capacity retention of 92.1% after 10 000 cycles. To highlight, fiber-shaped aqueous Zn/NH hybrid batteries based on ZnCuHCF cathode are successfully constructed, achieving admirable energy density of 85.73 mWh g and remarkable capacity retention of 85.2% after 12 500 cycles. This work paves the way for designing CuHCF with high capacity, high voltage and robust cycling stability in NH storage for applications in wearable aqueous batteries.
具有三维通道和高放电平台的六氰合铁酸铜（CuHCF）被广泛认为是一种极具潜力的铵离子（NH）存储阴极材料。然而，由于容量有限和结构不稳定，CuHCF的实际应用面临挑战，这主要源于单一活性位点和严重的 Jahn-Teller 畸变。在此，报道了一种创新的原位动态补偿策略，用于制备锌掺杂双活性位点 CuHCF（ZnCuHCF）作为用于 NH 存储的高能量和超稳定阴极材料。锌掺杂诱导 Cu e 轨道裂变，导致晶格畸变并达到稳定状态，而在 NH 嵌入过程中，主要在 Fe t 电子轨道上的变化有助于维持 ZnCuHCF 结构的稳定性。因此，在 23 m NHOTf + 0.5 m Zn(OTf) 水性电解质中的 ZnCuHCF 在 1 A g 时表现出 0.94 V 的高放电电位、121.7 mAh g 的高容量以及在 10000 次循环后令人印象深刻的 92.1% 的容量保持率。值得一提的是，成功构建了基于 ZnCuHCF 阴极的纤维状水性 Zn/NH 混合电池，实现了 85.73 mWh g 的令人钦佩的能量密度以及在 12500 次循环后 85.2% 的显著容量保持率。这项工作为设计在 NH 存储中具有高容量、高电压和稳健循环稳定性的 CuHCF 铺平了道路，可应用于可穿戴水性电池。
