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Potassium Nickel Iron Hexacyanoferrate as Ultra-Long-Life Cathode Material for Potassium-Ion Batteries with High Energy Density

Journal Article


Abstract


  • The abundant reserve and low price of potassium resources promote K-ion batteries (KIBs) becoming a promising alternative to Li-ion batteries, while the large ionic radius of K-ions creates a formidable challenge for developing suitable electrodes. Here Ni-substituted Prussian blue analogues (PBAs) are investigated comprehensively as cathodes for KIBs. The synthesized K1.90Ni0.5Fe0.5[Fe(CN)6]0.89��0.42H2O (KNFHCF-1/2) takes advantage of the merits of high capacity from electrochemically active Fe-ions, outstanding electrochemical kinetics induced by decreased band gap and K-ion diffusion activation energy, and admirable structure stability from inert Ni-ions. Therefore, a high first capacity of 81.6 mAh��g-1 at 10 mA��g-1, an excellent rate property (53.4 mAh��g-1 at 500 mA��g-1), and a long-term lifespan over 1000 cycles with the lowest fading rate of 0.0177% per cycle at 100 mA��g-1 can be achieved for KNFHCF-1/2. The K-ion intercalation/deintercalation proceeds through a facile solid solution mechanism, allowing 1.5-electron transfer based on low- and high-spins FeII/FeIII couples, which is verified by ex situ XRD, XPS, and DFT calculations. The K-ion full battery is also demonstrated using a graphite anode with a high energy density of 282.7 Wh��kg-1. This work may promote more studies on PBA electrodes and accelerate the development of KIBs.

Publication Date


  • 2020

Citation


  • Chong, S., Yang, J., Sun, L., Guo, S., Liu, Y., & Liu, H. K. (2020). Potassium Nickel Iron Hexacyanoferrate as Ultra-Long-Life Cathode Material for Potassium-Ion Batteries with High Energy Density. ACS Nano, 14(8), 9807-9818. doi:10.1021/acsnano.0c02047

Scopus Eid


  • 2-s2.0-85090077530

Start Page


  • 9807

End Page


  • 9818

Volume


  • 14

Issue


  • 8

Place Of Publication


Abstract


  • The abundant reserve and low price of potassium resources promote K-ion batteries (KIBs) becoming a promising alternative to Li-ion batteries, while the large ionic radius of K-ions creates a formidable challenge for developing suitable electrodes. Here Ni-substituted Prussian blue analogues (PBAs) are investigated comprehensively as cathodes for KIBs. The synthesized K1.90Ni0.5Fe0.5[Fe(CN)6]0.89��0.42H2O (KNFHCF-1/2) takes advantage of the merits of high capacity from electrochemically active Fe-ions, outstanding electrochemical kinetics induced by decreased band gap and K-ion diffusion activation energy, and admirable structure stability from inert Ni-ions. Therefore, a high first capacity of 81.6 mAh��g-1 at 10 mA��g-1, an excellent rate property (53.4 mAh��g-1 at 500 mA��g-1), and a long-term lifespan over 1000 cycles with the lowest fading rate of 0.0177% per cycle at 100 mA��g-1 can be achieved for KNFHCF-1/2. The K-ion intercalation/deintercalation proceeds through a facile solid solution mechanism, allowing 1.5-electron transfer based on low- and high-spins FeII/FeIII couples, which is verified by ex situ XRD, XPS, and DFT calculations. The K-ion full battery is also demonstrated using a graphite anode with a high energy density of 282.7 Wh��kg-1. This work may promote more studies on PBA electrodes and accelerate the development of KIBs.

Publication Date


  • 2020

Citation


  • Chong, S., Yang, J., Sun, L., Guo, S., Liu, Y., & Liu, H. K. (2020). Potassium Nickel Iron Hexacyanoferrate as Ultra-Long-Life Cathode Material for Potassium-Ion Batteries with High Energy Density. ACS Nano, 14(8), 9807-9818. doi:10.1021/acsnano.0c02047

Scopus Eid


  • 2-s2.0-85090077530

Start Page


  • 9807

End Page


  • 9818

Volume


  • 14

Issue


  • 8

Place Of Publication