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A Low‐Strain Potassium‐Rich Prussian Blue Analogue Cathode for High Power Potassium‐Ion Batteries
Author(s) -
Li Lin,
Hu Zhe,
Lu Yong,
Wang Chenchen,
Zhang Qiu,
Zhao Shuo,
Peng Jian,
Zhang Kai,
Chou ShuLei,
Chen Jun
Publication year - 2021
Publication title -
angewandte chemie
Language(s) - English
Resource type - Journals
eISSN - 1521-3757
pISSN - 0044-8249
DOI - 10.1002/ange.202103475
Subject(s) - cathode , prussian blue , potassium , intercalation (chemistry) , materials science , potassium ion battery , diffusion , graphite , chemical engineering , ionic radius , electrolyte , ion , chemistry , inorganic chemistry , electrochemistry , composite material , electrode , lithium vanadium phosphate battery , metallurgy , organic chemistry , thermodynamics , physics , engineering
Most of the cathode materials for potassium ion batteries (PIBs) suffer from poor structural stability due to the large ionic radius of K + , resulting in poor cycling stability. Here we report a low‐strain potassium‐rich K 1.84 Ni[Fe(CN) 6 ] 0.88 ⋅0.49 H 2 O (KNiHCF) as a cathode material for PIBs. The as‐prepared KNiHCF cathode can deliver reversible discharge capacity of 62.8 mAh g −1 at 100 mA g −1 , with a high discharge voltage of 3.82 V. It can also achieve a superior rate performance of 45.8 mAh g −1 at 5000 mA g −1 , with a capacity retention of 88.6 % after 100 cycles. The superior performance of KNiHCF cathode results from low‐strain de‐/intercalation mechanism, intrinsic semiconductor property and low potassium diffusion energy barrier. The high power density and long‐term stability of KNiHCF//graphite full cell confirmed the feasibility of K‐rich KNiHCF cathode in PIBs. This work provides guidance to develop Prussian blue analogues as cathode materials for PIBs.