Hollow structured SnO2/NxC composites: Preparation approach and promising performance in lithium-ion battery

Despite the high theoretical capacity as the anode material adopted in lithium-ion batteries, SnO2 materials undergo rapid capacity fading and low-rate performance due to the significant volume change and poor conductivity. This research proposes a straightforward approach to prepare hollow structured SnO2 spheres based on the N-dopped C coating layer (HS-SnO2@NxC) to overcome these problems. The structural and elemental characterizations were performed, and the cycling performance of HS-SnO2@NxC was systematically investigated. The presence of a hollow void in the HS-SnO2@NxC material allows for adaptation to volume changes during the charging and discharging process. Additionally, the outer framework of NxC strengthens the structural integrity of the spheres and facilitates the transfer of electrons and charges. These factors significantly improve the rate performance of the anode material. Owing to these advantages, HS-SnO2@NxC electrodes delivered a stable capacity of 610 mA.h/g at 0.25C after 750 cycles. Meanwhile, the great reversible rate performance of 76.7% was attained after a superior rate performance of 425 mA.h/g at 5C (1C=800 mA/g).