Defect-Free Prussian Blue Analogue as Zero-Strain Cathode Material for High-Energy-Density Potassium-Ion Batteries

Prussian blue analogues (PBAs) have been widely studied as cathodes for potassium-ion batteries (PIBs) due to their three-dimensional framework structure and easily adjustable composition. However, the phase transition behavior and [Fe(CN)6]4– anionic defects severely deteriorate electrochemical performances. Herein, we propose a defect-free potassium iron manganese hexacyanoferrate (K1.47Fe0.5Mn0.5[Fe(CN)6]·1.26H2O, KFMHCF-1/2) as the cathode material for PIBs. The Fe–Mn binary synergistic and defect-free effects can inhibit the cell volume change and octahedral slip during the K-ion insertion/extraction process, so that the phase transformation behavior (monoclinic ↔ cubic) is effectively inhibited,…

• NN
  National Natural Science Foundation of China

  Award: 52207248
• NP
  Northwestern Polytechnical University

  Award: 2022T024
• CP
  China Postdoctoral Science Foundation

  Awards: 2022M722606, 2021TQ0266
• NS
  Natural Science Basic Research Program of Shaanxi Province

  Award: 2022JQ-113
• BA
  Basic and Applied Basic Research Foundation of Guangdong Province

  Awards: 2021A1515110164, 2022A1515010208