Eldho Edison1 Madhavi Srinivasan1

1, Nanyang Technological University, Singapore, , Singapore

Recently, sodium-ion batteries have received a renewed interest due to the cheap and abundant sodium reserves and the electrochemical similarity to the existing lithium-ion batteries. However, it is quintessential to develop electrodes with high capacity and long calendar life to bring forth the successful implementation of sodium-ion batteries in real-world applications. Herein, we present the synthesis of intermetallic FeSn2 alloy particles through a facile solvothermal technique and fabrication of the FeSn2/Graphite composites via a high-energy ball milling technique. The pristine FeSn2 powder and the FeSn2/Graphite composites were characterized using X-ray diffraction and were found to be phase-pure with no impurities. Additionally, scanning electron microscopy and transmission electron microscopy techniques were employed to investigate the morphological features of the composites. Extensive electrochemical studies were carried out and the graphite content in the FeSn2/Graphite composite was optimized for improved cycling stability. Nearly 400 mAh g-1 sodiation capacity was retained for over 200 charge-discharge cycles. Moreover, the composite anode exhibited excellent stability at high current rates, suggesting their suitability for real-world applications including grid storage and hybrid electric vehicles.