A sodium manganese ferrocyanide thin film for Na-ion batteries

Abstract

A thin film of sodium manganese ferrocyanide, Na1.32Mn[Fe(CN)6]0.83·3.5H2O, exhibits discharge capacity (= 109 mA h g(-1)) and discharge voltage (3.4 V in average) at 0.5 C against Na in aprotic solvent. The ex situ XRD experiments reveal that the host framework remains cubic without showing any structural phase transition during the charge process. The discharge property is discernible up to 40 C.

Low Voltage Charge/Discharge Behavior of Manganese Hexacyanoferrate

“…Goodenough's group [7] reported charge/discharge properties of the SIB cathodes in a K-M-Fe(CN) 6 system (M = Mn, Fe, Co, Ni, Cu, Zn) even though their coulomb efficiency is poor. The coulomb efficiency is significantly improved in thin films of Na 1.32 Mn[Fe(CN) 6 ] 0.83 ·3.5H 2 O [8], and Na 1.6 Co[Fe(CN) 6 ] 0.9 ·2.9H 2 O [9]. They show high capacities of 109 and 135 mAh/g and average operating voltages of 3.4 and 3.6 V against Na/Na + , respectively.…”

“…The lower and upper cut-off voltages were 0.01 and 3.0 V, respectively. We note that the as-grown Mn-PBA film shows Li + /Na + deintercalation [5,8] at ≈3.5 V versus Li/Li + and ≈3.3 V versus Na/Na + . These redox potentials are above the upper cut-off voltage (=3.0 V), and, hence, the Mn-PBA does not show Li + /Na + deintercalation.…”

“…Among nanoporous materials, transition metal hexacyanoferrates or Prussian blue and its analogues (PBAs), denoted as A x M[Fe(CN) 6 ] y (A and M, are the alkali and transition metals, respectively), are most intensively investigated for LIBs [2][3][4][5][6][7][8] and sodium-ion secondary batteries (SIBs) [9][10][11][12][13]. The PBAs consist of three-dimensional cyano-bridged networks (jungle-gym type networks) of the transition metal, -M-NC-Fe-CN-M-, with periodic nano-cubes of 5 Å on each side [14,15].…”

Facile Method To Synthesize Na-Enriched Na1+xFeFe(CN)6 Frameworks as Cathode with Superior Electrochemical Performance for Sodium-Ion Batteries

“…After 400 cycles, the capacity of PB-5 was still 97% of the initial capacity, while the capacity retention of PB-1 was 91%, which was also higher compared with other cathode materials for sodium-ion batteries. [4][5][6][7][8][9][10][11][12][13][14][15][16][17] This demonstrates that the reduction of the vacancies and coordinating water in the Na1+xFe[Fe(CN)6] framework results in structural stability of the PB compound, which gives rise to a higher capacity and greater cycling stability during the charge-discharge processes. The discharge-charge curves with cycles of the Na1+xFe[Fe(CN)6] cathode are plotted in Figure S6.…”

“…Hence, it is crucial to develop a non-toxic, low-cost, high-capacity, stable cathode material for SIBs to ensure large-scale and long-term applications. Up to now, transition metal (M) oxides (NaxMO2+y), [4][5][6][7][8] phosphates, 9-12 fluorides, 13 and hexacyanoferrates [14][15][16][17] have been reported as cathode materials for SIBs. Few materials, however, can have both high capacity (> 100 mAh g-1) and long cycle life simultaneously.…”