Activation of Sodium Storage Sites in Prussian Blue Analogues via Surface Etching

Abstract

Sodium-ion battery technologies are known to suffer from kinetic problems associated with the solid-state diffusion of Na in intercalation electrodes, which results in suppressed specific capacity and degraded rate performance. Here, a controllable selective etching approach is developed for the synthesis of Prussian blue analogue (PBA) with enhanced sodium storage activity. On the basis of time-dependent experiments, a defect-induced morphological evolution mechanism from nanocube to nanoflower structure is proposed. Through in situ X-ray diffraction measurement and computational analysis, this unique structure is revealed to provide higher Na diffusion dynamics and negligible volume change during the sodiation/desodiation processes. As a sodium ion battery cathode, the PBA exhibits a discharge capacity of 90 mA h g, which is in good agreement with the complete low spin Fe(C) redox reaction. It also demonstrates an outstanding rate capability of 71.0 mA h g at 44.4 C, as well as an unprecedented cycling reversibility over 5000 times.

Ultrafine Prussian Blue as a High‐Rate and Long‐Life Sodium‐Ion Battery Cathode

“…Transmission electron microscopy (TEM) image further reveals that the primary particle size is ≈40 nm (Figure c,d), which is much smaller than those products via the solution method (>100 nm). The ultrafine size is helpful for rapid Na‐ion diffusion during the electrochemical process because of the shortened diffusion length . In the high‐resolution transmission electron microscopy (HRTEM) image of FePBA/16, clear lattice fringes corresponding to the (220) crystalline plane can be observed, which further confirms the high crystallinity.…”

A Heterostructure Coupling of Bioinspired, Adhesive Polydopamine, and Porous Prussian Blue Nanocubics as Cathode for High‐Performance Sodium‐Ion Battery

“…[ 16–18 ] In recent years, great efforts have been made to probe PB and its analogues as cathodes for industrial application in SIBs. [ 19–22 ] Despite their numerous advantages, there are still big challenges involved in greatly improving their first cycle coulombic efficiency, cycling stability, and rate performance. [ 23–25 ] Not only the structural irregularity, Fe(CN) 6 vacancies, and zeolitic water in the PB structure, but also its size and morphology have great effects on performance.…”

Hierarchical Engineering of Porous P2‐Na2/3Ni1/3Mn2/3O2 Nanofibers Assembled by Nanoparticles Enables Superior Sodium‐Ion Storage Cathodes

“…[1][2][3][4] However, the pursuit of applicable Na-ion storage electrode materials seems harder than the exploration of their Li-ion counterparts due to the larger size and heavier mass of Na + versus Li + . [7,8] Among the currently proposed cathode candidates, such as transition metal oxides (TMOs), [9][10][11][12][13][14][15][16][17] polyanion-type compounds, [18][19][20][21][22][23] Prussian blue analogues, [24,25] and organic salts, [26,27] layered transition metal oxides are particularly intriguing because of their 2D frameworks offering free Na-diffusion channels. [7,8] Among the currently proposed cathode candidates, such as transition metal oxides (TMOs), [9][10][11][12][13][14][15][16][17] polyanion-type compounds, [18][19][20][21][22][23] Prussian blue analogues, [24,25] and organic salts, [26,…”