Nickel hexacyanoferrate, a versatile intercalation host for divalent ions from nonaqueous electrolytes

Abstract

New energy storage chemistries based on Mg ions or Ca ions can theoretically improve both the energy density and reduce the costs of batteries. To date there has been limited progress in implementing these systems due to the challenge of finding a high voltage high capacity cathode that is compatible with an electrolyte that can plate and strip the elemental metal. In order to accelerate the discovery of such a system, model systems are needed that alleviate some of the issues of incompatibility. This report demonstrates the ability of nickel hexacyanoferrate to electrochemically intercalate Mg, Ca and Zn ions from a nonaqueous electrolyte. This material has a relatively high insertion potential and low overpotential in the electrolytes used in this study. Furthermore, since it is not an oxide based cathode it should be able to resist attack by corrosive electrolytes such as the chloride containing electrolytes that are often used to plate and strip magnesium. This makes it an excellent cathode for use in developing and understanding the complex electrochemistry of multivalent ion batteries.

Calcium‐Ion Batteries: Current State‐of‐the‐Art and Future Perspectives

“…PB analogs are an example of Metal Organic Framework structures and have been investigated widely recently as insertion electrodes for batteries . These materials have the general formula A x MFe(CN) 6 .…”

“…In a follow‐up study with nickel hexacyanoferrate Lipson et al[57a] found that this material could also reversibly intercalate Ca‐ions electrochemically from nonaqueous electrolytes although the initial capacity was only 60 mAh g −1 at a voltage of 2.6 V versus Ca/Ca 2+ and capacity retention with cycling was poor. These capacities are still too low for practical battery applications.…”

“…Preliminary reports of Ca‐Sn anodes are interesting and suggest the possibility of similar systems using other metals that are used for Na‐ion or Mg‐ion battery anodes, e.g., Sb, Bi, and mixed metal alloys. [57a,66] These options still need to be explored for CIBs.…”

On the Scope of XPS as Sensor in Coordination Chemistry of Transition Metal Hexacyanometallates

“…The net effect is an overlapping for the electron clouds of the involved metals (M, T). This explains the attractive properties of this family of materials as prototype of molecular magnets, which have been widely studied in the last decades The presence of two redox centers linked through the CN bridge and for some compositions also of an exchangeable alkali metal (A), has stimulated their study as materials for new generation of batteries, in electrochemical sensors, environmental remediation,, and for health care . For certain combinations of metals, e.g.…”

Probing the local structure of Prussian blue electrodes by 113Cd NMR spectroscopy

“…in both aqueous and non-aqueous electrolytes. [6][7][8][9][10][11][12][13][14][15] For example, Na2Fe[Fe(CN)6]·0.1H2O as a positive electrode material for non-aqueous Na-ion batteries exhibits a large specific capacity of 155 mAh/g at the average potential of 3.1 V vs. Na/Na + . 16 However, the reaction mechanism of the PBA electrodes have not been fully understood yet.…”