Long-life Na-rich nickel hexacyanoferrate capable of working under stringent conditions

Abstract

Prussian blue materials have been considered as ideal cathodes for sodium-ion batteries (SIBs) because of the unique open framework structure. Among those, nickel hexacyanoferrate (NiHCF) with a “zero strain” characteristics...

Scalable Preparation of Mn/Ni Binary Prussian Blue as Sustainable Cathode for Harsh-Condition-Tolerant Sodium-Ion Batteries

“…The agglomerated particle is composed of quasi-cubic particles with average particles size of ∼400 nm. The large particle size of Mn 0.5 Ni 0.5 -0.5 can effectively reduce corrosion and dissolution during cycling, and the multiedge structure is desirable for rapid Na + transportation at the electrode/electrolyte interface, which is beneficial for cycling stability and rate capability. , The TEM image in Figure b confirms the agglomerated structure, which is consistent with the SEM result. The elemental distribution of Mn 0.5 Ni 0.5 -0.5 was analyzed by high-angle annular dark field-scanning transmission electron microscopy (HAADF-STEM) and EDX mapping (Figure c–f).…”

“…As expected, elements of Na, Mn, Ni, Fe, C, N, and O are observed in the survey spectrum, where the oxygen signal comes from crystalline water. The peaks at 708.2 and 721.1 eV in the Fe 2p spectrum are related to Fe 2+ 2p 3/2 and Fe 2+ 2p 1/2 , respectively. , The peaks at 641.4, 645.8, 652.6, and 653.9 eV in the Mn 2p spectrum correspond to Mn II 2p 3/2 , Mn III 2p 3/2 , Mn II 2p 1/2 , and Mn III 2p 1/2 , respectively. , The bands at 856.1 and 873.9 eV in the Ni 2p spectrum are assigned to Ni 2+ 2p 3/2 and Ni 2+ 2p 1/2 , respectively, and the bands at 862.7 and 880.3 eV are the satellite peaks of Ni 2+ . , …”

“…Among various PBs, manganese-based hexacyanoferrate (Mn-PB) has a high energy density, but its cycling stability and rate capability need to be improved for practical applications. − By contrast, nickel-based hexacyanoferrate (Ni-PB) shows excellent cycling stability and rate capability, but its specific capacity is low with inactive Ni. − Thus, partial substitution of Mn with Ni (MnNi-PB) resulted in a combined merit of Mn-PB and Ni-PB, where the electrochemically inert Ni could alleviate structural deformation caused by Mn redox reactions . However, MnNi-PB produced by a simple coprecipitation method usually exhibited unsatisfied electrochemical performance with uncontrolled composition and morphology. − Therefore, it is necessary to improve preparation for performance enhancement.…”

Nickel hexacyanoferrate/graphene thin film: a candidate for the cathode in aqueous metal-ion batteries

“…Nickel hexacyanoferrate (NiHCFe) presents Ni II and Fe II species with a Fe–CN–Ni coordination and has shown very good capacities as an electrode in both aqueous Na- and K-ion batteries (as high as 106 and 87 mA h g −1 at 0.01 A g −1 , respectively). 11,12 However, as observed for the whole class of HCMs, NiHCFe present low stability over long charge–discharge cycling and drastic losses in the capacity retention at high current densities. These troubles can be overcome by preparing carbon-based nanocomposites.…”

Pilot‐Scale Synthesis Sodium Iron Fluorophosphate Cathode with High Tap Density for a Sodium Pouch Cell

“…Layered transition metal oxides and Prussian blue analogs have been paid much attention to promising candidate cathodes due to their advantages of specific capacity and working potential corresponding to high energy density, but exist inherent challenges. [23][24][25][26][27][28][29][30][31] For example, the most layered transition metal oxides are not very stable against ambient air. [23][24][25][26] The Prussian blue analogs have safety issues because cyanide groups are released as toxic cyanides above 200 °C.…”