Researchers at CIC energiGUNE are advancing sodium-ion battery technology by tailoring different chemistries to specific applications. According to Jon Ajuria, head of the sodium-ion research line, no single sodium chemistry dominates; instead, three main families—Prussian Blue-type materials, layered oxides and polyanionic compounds—are each optimized for distinct performance and cost requirements.
Prussian Blue-type materials rely on abundant raw materials and straightforward manufacturing, making them a low-cost option for stationary storage where energy density is less critical.
Layered oxides offer the highest energy density among sodium systems, bringing them closer to lithium-based chemistries like lithium iron phosphate. However, they face challenges related to structural degradation during cycling.
Polyanionic materials provide robust structural stability and predictable lifetimes, but at lower energy densities that may limit their use in space- or weight-sensitive applications.
Selecting the appropriate chemistry involves balancing cost, cycle life, safety, operating temperature and material availability against the intended use case. For example, stationary installations can prioritize durability and affordability, while mobility solutions demand higher energy per volume or weight. System-level considerations—such as overall design impacts and total cost per usable kilowatt-hour—also guide the choice.
Key scientific hurdles include improving energy density, controlling degradation mechanisms at the electrode-electrolyte interface and ensuring reproducible synthesis for large-scale production. Ajuria highlights the importance of interface stability: unstable interfaces in sodium cells can accelerate capacity fade and reduce efficiency. Doping and surface coatings are critical strategies for enhancing material stability, reducing unwanted side reactions and extending cycle life.
Advanced electrolytes, particularly fluorine-free or high-concentration formulations with targeted additives, are emerging as active contributors to performance. These developments also benefit from synergies with lithium battery infrastructure, as many production processes and cell formats are transferable, lowering entry barriers for industrial adoption.
Early commercial deployments of sodium-ion batteries are expected in applications where cost and robustness outweigh energy density constraints, such as grid storage, off-grid systems, micromobility and lead-acid battery replacements.
Between 2026 and 2030, researchers aim to validate laboratory performance under real-world conditions, scale up manufacturing without compromising quality and establish pilot use cases to build market confidence. At this stage, the primary challenge lies in translating scientific progress into reliable, cost-competitive industrial processes.
Source: CIC energiGUNE Blog
