Prussian Blue Analogues for Non‐Aqueous Sodium‐Ion and Potassium‐Ion Batteries: The Landscape From Lab‐Scale Optimizations Toward Practical Applications

Why It Matters

By overcoming intrinsic challenges, PBAs could provide low‑cost, high‑performance cathodes, accelerating commercialization of sodium‑ and potassium‑ion batteries and diversifying the battery market beyond lithium.

Key Takeaways

• Simple synthesis, low cost enable scalable production
• Crystal water content critically impacts voltage and capacity
• Particle size reduction improves rate capability and cycle life
• Interfacial stability governs safety in non‑aqueous cells
• Optimized PBAs approach energy densities comparable to layered cathodes

Pulse Analysis

Prussian blue analogues have attracted attention as a next‑generation cathode platform for sodium‑ion and potassium‑ion batteries, two chemistries poised to complement lithium‑ion technology. Their open framework accommodates large alkali ions, while the inexpensive precursors and aqueous synthesis routes enable mass production at a fraction of the cost of conventional layered oxides. As the market seeks sustainable, geographically diversified supply chains, PBAs offer a compelling blend of structural robustness and material abundance, positioning them as viable candidates for large‑scale stationary storage and electric‑vehicle applications.

Technical performance, however, hinges on precise control of crystal water, defect density, and particle morphology. Excess crystal water can depress operating voltage and trigger irreversible phase changes, whereas engineered vacancies improve electronic conductivity and ion diffusion pathways. Nanoscale particle engineering shortens diffusion lengths, boosting rate capability and extending cycle life, but must be balanced against surface reactivity that can compromise interfacial stability. Recent studies demonstrate that surface coatings and electrolyte additives mitigate side reactions, enhancing safety in non‑aqueous environments and narrowing the performance gap with established cathodes.

The review’s roadmap emphasizes translating these laboratory insights into manufacturable processes. Scalable precipitation methods, coupled with in‑line water‑content monitoring and controlled annealing, can produce uniform PBA powders ready for electrode fabrication. By aligning material optimization with cost‑effective production, PBAs could achieve energy densities approaching 150 Wh kg⁻¹ while maintaining the low‑cost advantage that drives sodium‑ and potassium‑ion battery adoption. This convergence of performance, safety, and sustainability signals a pivotal shift toward diversified battery chemistries, offering the industry a pragmatic pathway to meet growing energy‑storage demand.