In this paper, the efficiency of Iron-Hexacyanoferrate (FeHCF) and Copper-Hexacyanoferrate (CuHCF) as the cathode materials for using in the energy storage application have been investigated using Density Functional Theory. The changes of their lattice parameters due to the insertion of K⁺ cation were explored. It was found that these changes for CuHCF are less than FeHCF. FeHCF, KFHCF, CuHCF, KCuHCF, and K₂CuHCF are found to have a half-metallic nature. In contrast, K₂FeHCF is found to be a diamagnetic insulator. K⁺ diffusion through the FeHCF and CuHCF frameworks have the energy barrier of 1.46 eV and 1.00 eV, respectively.

中文翻译：

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铜和铁六氰基高铁酸盐作为钾离子电池的阴极材料：第一性原理研究

本文利用密度泛函理论研究了六价高铁酸铁（FeHCF）和六价高铁酸铜（CuHCF）作为阴极材料在储能应用中的效率。研究了由于K ⁺阳离子的插入而引起的晶格参数的变化。发现CuHCF的这些变化小于FeHCF。发现FeHCF，KFHCF，CuHCF，KCuHCF和K ₂ CuHCF具有半金属性质。相反，发现K ₂ FeHCF是抗磁性绝缘体。通过FeHCF和CuHCF框架的K ⁺扩散的能垒分别为1.46 eV和1.00 eV。