Comprehensive Study of Sodium Copper Hexacyanoferrate, as a Sodium-Rich Low-Cost Positive Electrode for Sodium-Ion Batteries

Abstract

Prussian blue and its analogues are broadly recognized as positive electrodes for sodium-ion batteries, owing to their three-dimensional framework, low cost, and high capacity. However, they suffer from lower cell voltage and poor capacity utilization, which lead to low energy density. Herein, we report sodium-rich copper hexacyanoferrate (NaCuHCF) as a high potential cathode (∼3.25 V vs Na+|Na) with high purity and crystallinity, synthesized via the coprecipitation method. The cathode is used without any surface coating or modification. X-ray diffraction (XRD) along with Rietveld refinement confirms the cubic crystal lattice phase, which possesses the Fm3m space group. The NaCuHCF cathode exhibits an initial specific capacity of 64 mA h g–1 at a current rate of 0.05 A g–1 with the electrochemically active Fe2+/Fe3+ redox couple. It shows excellent cycling stability retaining 93% of the capacity over 100 cycles, with merely 0.07% capacity fading per cycle. Moreover, the cell (Na||NaCuHCF) delivers one of the highest energy density of 203 W h kgcathode –1 at a current rate of 0.05 A g–1 with excellent rate capability and minimum voltage hysteresis. Kinetic investigations reveal that the Na+ storage mechanism is controlled by surface capacitive behavior mainly at a high current rate. Additionally, the Na+ (de)­intercalation mechanism is investigated by XRD, X-ray photoelectron spectroscopy, X-ray absorption near-edge structure, and extended X-ray absorption fine structure analyses.

Quantification of Neuronal Cell-Released Hydrogen Peroxide Using 3D Mesoporous Copper-Enriched Prussian Blue Microcubes Nanozymes: A Colorimetric Approach in Real Time and Anticancer Effect

“…Furthermore, it shows that the original PB phase was not affected by the introduction of Cu 2+ doping as no distinguishable new characteristic peak was observed in Meso-Cu-PBMCs. This finding is consistent with the previous research. ,, The lattice parameters of PBMCs, Meso-PBMCs, and Meso-Cu-PBMCs were calculated to be 10.16, 12.16, and 15.23 Å, respectively. Additionally, the average crystalline size was determined to be 53.16 nm for PBMCs, 56.7 nm for Meso-PBMCs, and 63.5 nm for Meso-Cu-PBMCs.…”

“…This finding is consistent with the previous research. 36,54,55 The lattice parameters of PBMCs, Meso-PBMCs, and Meso-Cu-PBMCs were calculated to be 10.16, 12.16, and 15.23 Å, respectively. Additionally, the average crystalline size was determined to be 53.16 nm for PBMCs, 56.7 nm for Meso-PBMCs, and 63.5 nm for Meso-Cu-PBMCs.…”

Pillarquinone-based sodium-ion batteries using a highly concentrated electrolyte

“…Typically, the surface-controlled capacitive current increases with the scan rate. 61 Figure 3b shows that this is also the case for the P5Q@CMK-3 composite electrode, where the capacitive-controlled current increases from 78% to 94% with growing scan rate from 0.1 to 0.6 mV s −1 . Thus, the fast kinetics of the composite electrode are likely enabled by the porous morphology of the CMK-3 carbon (Figure S6), which effectively reduces the length of the ion diffusion pathways between electrolyte and redox-active center and accelerates the electrochemical redox reactions.…”

Hexagonal Boron Nitride as Anode for Sodium Ion Battery – A Reality Check!

“…Furthermore, a sharp increase in the low frequency impedance for BNNP and inclination towards the real axis indicated increased adsorption of Na + in the case of BNNP. 33 The impedance study validates that regardless of the large surface area compared to BNB, BNNP demonstrates sluggish sodium ion transport and much enhanced adsorption (irreversible) leading to a poor electrochemical performance in long run.…”