Low-temperature sodium-ion batteries: challenges, engineering strategies, safety considerations, and future directions

Abstract

Sodium-ion batteries (SIBs) present a sustainable and cost-effective alternative to lithium-ion batteries (LIBs) for low-temperature (LT) applications, leveraging sodium abundance and reduced geopolitical risks. While SIBs exhibit superior capacity retention in cold environments compared with LIBs, their adoption faces challenges including sluggish Na⁺ diffusion, increased electrolyte viscosity, unstable electrode–electrolyte interfaces, and electrode structural degradation. This review analyzes the mechanisms of LT performance limitations and evaluates strategies to overcome them. Electrolyte engineering, using optimized sodium salts, multi-solvent formulations, and functional additives, enhances ionic conductivity and stabilizes interfaces. Electrode modifications, such as defect engineering, nanostructuring, elemental doping for cathodes, and morphology tuning with porous architectures for anodes, mitigate kinetic barriers and volume expansion. Integrating advanced electrolytes with tailored electrodes improves charge storage efficiency and cycling stability at sub-zero temperatures, enabling applications in Arctic infrastructure, aerospace, and renewable energy storage. However, gaps persist in understanding solid–electrolyte interphase (SEI) formation, material scalability, thermal safety studies, and energy density optimization. Future research priorities include computational modeling of ion-transport mechanisms, sustainable recycling protocols, and hybrid systems with thermal management. Bridging fundamental insights with practical engineering charts a path towards high-performance LT-SIBs, crucial for decarbonizing energy systems in extreme environments and advancing global energy resilience.