Activating C‐Coordinated Iron of Iron Hexacyanoferrate for Zn Hybrid‐Ion Batteries with 10 000‐Cycle Lifespan and Superior Rate Capability

Abstract Prussian blue analogue (PBA)‐type metal hexacyanoferrates are considered as significant cathodes for zinc batteries (ZBs). However, these PBA‐type cathodes, such as cyanogroup iron hexacyanoferrate (FeHCF), suffer from ephemeral lifespan (≤1000 cycles), and inferior rate capability (1 A g −1 ). This is because the redox active sites of multivalent iron (Fe(III/II)) can only be very limited activated and thus utilized. This is attributed to the spatial resistance caused by the compact cooperation interaction between Fe and the surrounded cyanogroup, and the inferior conductivity. Here, it is found that high‐voltage scanning can effectively activate the C‐coordinated Fe in FeHCF cathode in ZBs. Thanks…

• CU
  City University of Hong Kong