Critical Size of a Nano SnO2 Electrode for Li-Secondary Battery

SnO 2 nanoparticles with different sizes of ∼3, ∼4, and ∼8 nm were synthesized using a hydrothermal method at 110, 150, and 200 °C, respectively. The results showed that the ∼3 nm-sized SnO 2 nanoparticles had a superior capacity and cycling stability as compared to the ∼4 and ∼8 nm-sized ones. The ∼3 nm-sized nanoparticles exhibited an initial capacity of 740 mAh/g with negligible capacity fading. The electrochemical properties of these nanoparticles were superior to those of thin-film analogues. Transmission electron microscopy (TEM) and X-ray diffraction (XRD) confirmed that the ∼3 nm-sized SnO 2 nanoparticles after electrochemical tests did not aggregate into larger Sn clusters, in contrast to those observed with the ∼4 and ∼8 nm-sized ones.