Sodium to cesium ions: a general ladder mechanism of ion diffusion in prussian blue analogs

Abstract

Cations in Prussian blue analogs (PBA) follow a ladder mechanism of ion transport. Defective regions in the crystal slow diffusion by blocking transport, while intact regions slow diffusion by trapping ions.

Engineering a defect-rich Prussian blue analog composite for enhanced Cs+ removal performance

“…These results suggested that the K + -Cs + exchange process was accompanied by the elimination of lattice water from the defect sites. Combined with the reported adsorption mechanism, where the Cs + adsorption process tends to occur at the defects existing in the PBA sub-cube faces, [10][11][12] for the Zn-PBA/NPC composite, K + might exchange with Cs + in the form of hydrated K(OH 2 ) + at the defects sites close to the Zn-PBA crystal face.…”

“…10 Nordstrand et al proposed a ladder mechanism to understand the suppression of Cs + adsorption by a low vacancy defect density, suggesting the positive effects of PBA defects on Cs + adsorption. 11 Ishizaki et al found that Cs + was preferably adsorbed via the hydrophilic defects in PBA, and a high defect content is beneficial for the uptake of Cs + . 12 Therefore, increasing the defects in PBA could effectively promote its Cs + adsorption performance.…”

“…17 The defects in Zn–PBA were occupied by water. 11 Therefore, the water content of Zn–PBA could reflect the number of defects. The TG measurements of pure Zn–PBA powder and Zn–PBA/NPC suggested that the water contents of the Zn–PBA powder and Zn–PBA/NPC composite were 4.8% and 13.9%, respectively, which were obtained by calculating the weight loss below 300 °C (Fig.…”

Rhombohedral (R) Prussian White as Cathode Material: An Ab‐initio Study

“…As the high vacancy limit diffusion in C-PW is already studied elsewhere, even including the presence of defects, [57,58] we will focus our attention on the comparison of the sodium-ion migration in C-PW and R-PW in the low vacancy limit. The minimum energy path for the sodium migration in the low vacancy limit is illustrated in Figure 5.…”

Ion Mobility in Crystalline Battery Materials

“…Furthermore, there are the reports of Nordstrand et al utilizing a semi-empirical tight binding approach to determine the charge carrier mobility. [154,155] They report energy barriers for diffusion events from one face centered site to another to exhibit an energy barrier of 0.32-0.39 eV. The diffusion through a body-centered void is comparatively unfavored, showing energy barriers of 0.69 eV.…”