An All‐Prussian‐Blue‐Based Aqueous Sodium‐Ion Battery

Abstract

Aqueous rechargeable sodium‐ion batteries have received great attention as an alternative to meet the growing demand of large‐scale electrochemical energy storage systems due to the earth‐abundant and low‐cost sodium resources. In this study, an all Prussian‐blue‐based aqueous sodium‐ion battery is constructed using copper and iron‐based Prussian blue analogues as cathode and anode, respectively, and neutral NaNO3 solution as electrolyte. The battery delivers an average output voltage of 0.70 V, a specific capacity of 50 mAh g−1, and good rate capability with ∼86 % capacity retention over 250 cycles at 5 C. Moreover, the cathode, anode, and electrolyte materials are inexpensive, environmentally friendly, and inherently safe, which is particularly attractive for large‐scale energy storage applications.

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

“…Among the viable KIB anodes, graphite gives a higher full‐cell voltage (3.4‒3.5 V) [ 29,86 ] than K 2 TP (2.7‒3.3 V) [ 208 ] and super P (2.5 V). [ 120 ] As to the aqueous batteries for both AM ions, the voltage output is lower than that of nonaqueous batteries, lying in the range of 0.6‒1.7 V for different anodes such as NaTi 2 (PO 4 ) 3 , [ 123 ] active carbon, [ 20 ] FeHCFs, [ 225–227 ] and MnMn(CN) 6 . [ 13,16 ] The operation current density of the aqueous full cells can be higher than normally used in nonaqueous batteries, which can readily reach several A g ‒1 as a compensation as the low voltage and capacity.…”

Structure and Properties of Prussian Blue Analogues in Energy Storage and Conversion Applications

“…[ 136–140 ] Table 1 provides some previously reported PBA‐based full batteries, including Na‐ion, K‐ion, Zn‐ion, Mg‐ion, and Al‐ion full batteries. There exist a lot of combinations of anode materials and electrolytes, taking the Na‐ion batteries as example, the anode materials can be TiS 2 , [ 84 ] NaTi 2 (PO 4 ) 3 , [ 75 ] Na foil, [ 85 ] FeHCF, [ 141 ] and KMn[Cr(CN) 6 ], [ 115 ] etc., and the applied aqueous/non‐aqueous electrolytes are selected based on their electrochemical windows. For aqueous Zn‐ion batteries, Zn‐based anode is promising in future practical applications.…”

Advanced Post‐Potassium‐Ion Batteries as Emerging Potassium‐Based Alternatives for Energy Storage

“…Currently, the extensively studied cathode materials are PB and PBAs because they possess open framework, large‐size ion channels, and plenty of active sites. [ 139 ] The general formula of PBAs is A x M[Fe(CN) 6 ] y ·ZH 2 O (A: alkali metal ion; M: transition metal ion; 0 ≤ x ≤ 2; y < 1). Electrochemical processes of PBAs can be single or double electrons transportation process, which is based on the types of redox sites because of the difference in transition metal ions of PBAs.…”