Prussian Blue Analogues for Sodium-Ion Battery Applications

Prussian blue analogues (PBAs) constitute a versatile family of open‐framework metal–organic compounds characterised by a three‐dimensional network of transition‐metal centres bridged by cyanide ligands. Their rigid lattice accommodates sodium ions in interstitial sites, offering high theoretical capacities (up to ~170 mAh g−1), low material cost and straightforward synthesis via precipitation. Nevertheless, the presence of structural water, framework vacancies and inherently low electronic conductivity can undermine cycle life, rate performance and initial Coulombic efficiency. Current strategies to address these challenges encompass precise control of crystalline phase and hydration, surface coatings, multivalent metal doping and entropy‐driven compositional disorder. By stabilising the host framework and enhancing ion diffusivity, these advances aim to deliver safe, scalable and sustainable sodium‐ion batteries for grid and large‐scale energy storage.

Research from Nature Portfolio

Recent studies have demonstrated that a controlled precipitation methodology can produce highly crystalline rhombohedral PBAs whose structure undergoes reversible transitions among rhombohedral, cubic and tetragonal phases during sodium‐ion (de)intercalation. These materials exhibit high initial Coulombic efficiency, outstanding rate capability and stable full‐cell cycling for over 1000 cycles. In addition, the discovery of a monovalent manganese redox couple in manganese‐based PBAs has unlocked a high‐rate, long‐life anode material. The integration of an organic–aqueous co‐solvent electrolyte effectively suppresses PBA solubility, enabling full‐cell configurations that retain more than 95 % of their initial capacity after 1000 cycles.

Prussian Blue Analogues for Sodium-Ion Battery Applications publication trend

The graph below shows the total number of articles in prussian blue analogues for sodium-ion battery applications across all publications each year (not limited to Nature Index journals).

Technical terms

Prussian blue analogue: A metal–organic framework of general formula AₓM[Fe(CN)₆]ᵧ·zH₂O, where A is an alkali ion and M is a transition metal, used as a rechargeable battery electrode.

Rhombohedral phase: A crystal lattice characterised by equal lattice parameters with oblique angles, offering enhanced structural stability during ion (de)insertion.

Coulombic efficiency: The ratio of charge extracted during discharge to the charge inserted during charging, indicating reversibility of electrochemical reactions.

Configurational entropy: The thermodynamic quantity reflecting the degree of compositional disorder in a multicomponent system, which can stabilise structure and suppress phase transitions.

Vacancy: A missing atom or ion in the crystalline lattice, influencing ionic mobility and capacity retention.

References

1. Reversible structural evolution of sodium-rich rhombohedral Prussian blue for sodium-ion batteries. Nature Communications (2020).
2. Monovalent manganese based anodes and co-solvent electrolyte for stable low-cost high-rate sodium-ion batteries. Nature Communications (2018).
3. Achieving a superior Na storage performance of Fe‐based Prussian blue cathode by coating perylene tetracarboxylic dianhydride amine. Carbon Energy (2024).
4. High‐Entropy Metal–Organic Frameworks for Highly Reversible Sodium Storage. Advanced Materials (2021).
5. Ternary Ni‐based Prussian blue analogue with superior sodium storage performance induced by synergistic effect of Co and Fe. Carbon Energy (2021).