Core-Shell Antimony and Hard Carbon Anode Boosts Sodium-Ion Battery Capacity and Cycle Life

Researchers report that a core-shell nanocomposite of antimony and hard carbon improves sodium-ion battery anode performance. In tests published in the Journal of Materials Science, the Sb@HC/HC composite with a 6:4 mass ratio delivered a charge capacity of 482.4 mAh g-1 at 100 mA g-1, with an initial Coulombic efficiency of 79.7%. After 100 cycles it retained 460.1 mAh g-1, about 95.4% of the starting capacity. Antimony offers high capacity but poor cycling stability, while hard carbon has a suitable operating potential but low capacity. The core-shell structure is meant to combine the strengths of both and limit the degradation that typically plagues antimony anodes. The authors say the approach points toward more practical sodium-ion batteries, which matter for stationary storage because sodium is cheaper and more abundant than lithium. This is lab-scale work, not a commercial product yet, so the next question is whether the manufacturing process can scale at reasonable cost. Still, any progress on sodium-ion anodes helps the case for storage that does not depend on lithium supply chains.