Effect of Particle Size and Anion Vacancy on Electrochemical Potassium Ion Insertion into Potassium Manganese Hexacyanoferrates
Effect of Particle Size and Anion Vacancy on Electrochemical Potassium Ion Insertion into Potassium Manganese Hexacyanoferrates
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DOI：
10.1002/cssc.202002628
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发表时间：
2021-01-14
期刊：
影响因子：
8.4
通讯作者：
Komaba, Shinichi
中科院分区：
文献类型：
--
作者：
Hosaka, Tomooki;Fukabori, Taiga;Komaba, Shinichi
铁氰化锰钾（KMnHCF）由于其高能量密度而可用作钾离子电池的正极。通过实验数据和理论计算研究了KMnHCFs的粒径和[Fe（CN）（6）]（n-）空位对KMnHCFs电化学嵌钾的影响。当合成和测试接近化学计量的KMnHCF时，发现较小的颗粒尺寸对于在容量和倍率性能方面实现上级电化学性能是重要的。然而，即使在较大颗粒的情况下，引入适当数量的阴离子空位使KMnHCF表现出相当的电极性能。电化学测试和密度泛函理论计算表明，阴离子空位的存在促进了K+离子的扩散，实现了良好的电化学性能。结构设计，包括晶体空位和颗粒尺寸，是其作为正极的高性能的关键。
Potassium manganese hexacyanoferrate (KMnHCF) can be used as a positive electrode for potassium-ion batteries because of its high energy density. The effect of particle size and [Fe(CN)(6)](n-) vacancies on the electrochemical potassium insertion of KMnHCFs was examined through experimental data and theoretical calculations. When nearly stoichiometric KMnHCF was synthesized and tested, smaller particle sizes were found to be important for achieving superior electrochemical performance in terms of capacity and rate capability. However, even in the case of larger particles, introducing a suitable number of anion vacancies enabled KMnHCF to exhibit comparable electrode performance. Electrochemical tests and density functional theory calculations indicated that anion vacancies contribute to the enhancement of K+ ion diffusion, which realizes good electrochemical performance. Structural design, including crystal vacancies and particle size, is the key to their high performance as a positive electrode.