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Electrochemical Analysis of the Mechanism of Potassium‐Ion Insertion into K‐rich Prussian Blue Materials
Author(s) -
Levin Eduard E.,
Kokin Aleksandr A.,
Presnov Denis E.,
Borzenko Andrei G.,
Vassiliev Sergey Yu.,
Nikitina Victoria A.,
Stevenson Keith J.
Publication year - 2020
Publication title -
chemelectrochem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.182
H-Index - 59
ISSN - 2196-0216
DOI - 10.1002/celc.201901919
Subject(s) - prussian blue , electrochemistry , ion , cyclic voltammetry , potassium , overpotential , phase (matter) , chemistry , materials science , inorganic chemistry , analytical chemistry (journal) , electrode , organic chemistry
The electrochemical insertion patterns of potassium‐rich Prussian blue (PB) materials with different compositions and particle sizes were systematically compared, which allows us to deduce correlations between the influence of particle morphology and material structure on the potassium‐ion insertion mechanisms in aqueous solutions. Although structural analysis indicates that no first‐order phase transitions occur for nanosized K‐rich Prussian blue particles upon potassium‐ion (de)insertion, the electrochemical data (galvanostatic charge/discharge, cyclic voltammetry, small‐ and large‐amplitude potential step experiments) suggest other outcomes related to the two‐phase insertion mechanism for all explored PB samples. However, even in a case whereby the phase transformation is not accompanied by abrupt changes in the crystal structure, the two‐phase mechanism dominates all of the essential practical characteristics of performance of this cathode material, such as hysteresis (overpotential) between charge and discharge steps and the measured diffusivities of potassium‐ions during charge and discharge. The formalism presented herein provides a basis for quantitatively assessing ion insertion and deinsertion parameters unique to PB analogues.