Beyond blue: Unlocking the electroactivity of anion linkers in Prussian blue analogues

As the world continues to face one crisis after another, the demand for renewable energy and sustainable materials supporting the delivery of renewable energy is stronger than ever.

Prussian blue analogues (PBAs) as electrodes in energy storage devices such as batteries show significant promise in terms of cost and sustainability, however, they are lacking in terms of volumetric energy density.

This project aims to design high capacity electrodes for non‑aqueous batteries based on a subclass of PBAs known as transition metal nitroprussides (TM-NPs). TM-NPs are similar in structure and composition to PBAs except for the presence of electroactive nitrosyl ligands.

The presence of both cationic and anionic redox centers in TM-NPs potentially doubles the specific energy density relative to parent PBA compounds.

The project will explore the role of composition and crystal structure on the initial and reversible electrochemical storage capacity of TM-NPs. Six compounds adopting two different crystal structures will be synthesized and electrochemically tested.

The structural and electronic changes during ion insertion will be studied via a multi-technique approach implementing operando methods at synchrotron and neutron facilities.

The project will thus elucidate the factors which drive utilization of all redox centers and produce a new class of electrode materials for sustainable batteries.