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

Abstract

Prussian blue analogs (PBAs) have attracted much attention as cathodes in sodium‐ion batteries due to their stable crystalline structure, high theoretical capacities, and facile synthesis. However, PBAs synthesized by the conventional precipitation method usually have the drawbacks of poor rate performance and cycling stability. Herein, the ball‐milling method is developed to prepare the ultrafine high‐quality Prussian blue. Benefited from its good crystallinity and ultrafine particle size of 40 nm, the obtained Na0.9Fe[Fe(CN)6]0.96 exhibits an outstanding cycling stability and rate capability, which can deliver a specific capacity of 106 mAh g−1 at 30 °C, maintaining 80% capacity after 500 cycles at 10 °C. The results show that a size effect can contribute to the enhancement of electrochemical kinetics of PBAs, and the scalable production of high‐performance PBAs can be anticipated based on the ball‐milling method.

Controlled scalable synthesis of yolk‐shell antimony with porous carbon anode for superior Na‐ion storage

“…These peaks can be assigned to redox reactions of Fe III /Fe II ions present in high‐spin (connected to N, Fe III ) and low‐spin (connected to C, Fe II ) octahedral during desodiation and sodiation (Figure 9B). [ 30,31 ] Figure 9C shows the cycling performance of Na//Na x Fe[Fe(CN) 6 ] cathode in half cell configuration at a specific current of 0.1 Ag –1 . The Na x Fe[Fe(CN) 6 ] cathode demonstrated a highly stable cycling performance for Na‐ion storage and deliver a discharge capacity ∼142 mAhg –1 with an associated Coulombic efficiency of ∼99.4% and capacity retention of ∼94% after 100 cycles.…”

Hexacyanoferrate‐Type Prussian Blue Analogs: Principles and Advances Toward High‐Performance Sodium and Potassium Ion Batteries

“…In addition to the synergetic strategies as discussed above, some studies are dedicated to the optimization of organic electrolytes from the aspect of salts, [ 111,207 ] solvents, [ 207–212 ] and additives [ 32 ] to minimize the negative effect of water on the electrochemical performances of HCFs. For aqueous batteries, the major efforts have been devoted to the use of high‐concentration aqueous electrolytes [ 22,101,213 ] and electrolyte additives.…”

Cathodes for Aqueous Zn‐Ion Batteries: Materials, Mechanisms, and Kinetics

“…There are a large number of interstitial sites in Prussian blue analogs (PBAs) crystal structures, which can act as the storage sites for some ions, especially Mg 2+ , Zn 2+ , and Al 3+ [136–142] . The generic formula of a PBA system can be roughly represented as A x M A y [M B (CN) 6 ] z ⋅ n H 2 O, where M A and M B are usually transition metal atoms (Mn, Fe, Co, Ni, Cu, or Zn), and A is usually an alkali metal atom (Li, Na, or K).…”

“…There are al arge number of interstitial sites in Prussian blue analogs( PBAs)c rystal structures, which can act as the storage sites for some ions, especially Mg 2 + ,Z n 2 + ,a nd Al 3 + . [136][137][138][139][140][141][142] The generic formula of aP BA system can be roughlyr epresented as A x M Ay [M B (CN) 6 ]z•n H 2 O, where M A and M B are usually transition metal atoms (Mn, Fe, Co, Ni, Cu, or Zn), and Ai su sually an alkali metal atom (Li, Na,o rK ). M A and M B can be the same elemento rd ifferent elements, which are distinguishedb yt heir different oxidation states andt heir spin states.…”