Overview on Sodium Ion Batteries: Anode, Cathode, and Electrolytes

ABSTRACT Sodium‐ion batteries (SIBs) are an appealing alternative to lithium‐ion technology, particularly for stationary energy storage, due to their lower cost, greater resource availability, and environmental sustainability. However, the cost advantages of stationary SIBs are inadequate to ensure widespread commercial use. Sodium ions have slower ionic transit and a lower energy density than lithium ions due to their bigger size and atomic weights. This constraint, however, can be overcome by the high‐rate capability of sodium‐based materials. SIB's key characteristics include high rate capability, compatibility for all climates, and total recyclability, which, when combined with cost savings, make them ideal for large‐scale energy storage systems. As a result, SIBs offer great potential for real‐world applications. Current SIBs have specific capacities ranging from 100 to 150 mAh/g and energy densities of around 100–150 Wh/kg. Although these figures are lower than those for high‐performance lithium‐ion batteries (LIBs), current research is gradually closing the gap. One of the primary goals for SIBs is to increase energy density to more than 200 Wh/kg and extend cycle life beyond 2000 cycles. Advanced cathode materials, like sodium manganese‐based compounds and sodium iron phosphate, are being studied, as well as new anode materials like hard carbon. Looking ahead, the future of SIBs is bright. According to BloombergNEF, SIBs might grab 23% of the stationary storage market by 2030, equivalent to more over 50 GWh. However, if technology improvements speed and production processes are optimized using equipment similar to that used in LIBs, these forecasts may be exceeded.