SnO2 nanoparticles encapsulated by curved graphite layers as anode materials for Li-ion batteries with high performances

• SnO2 nanoparticles are encapsulated by defective curved graphite layers.
• SnO2 nanocapsules can promote the electron transfer and Li+ diffusion.
• SnO2 nanocapsules can relieve the volume change during the charge/discharge cycles.
• SnO2 nanocapsules exhibit the capacity of 1253 mAh g−1 after 500 cycles at 0.5 A g−1.
• SnO2 nanocapsules show the high rate performance of 590.4 mAh g−1 at 20 A g−1.

We reported the preparation of dispersive SnO2 nanoparticles completely encapsulated by defective curved graphite layers. X-ray diffraction, Raman spectroscopy, transmission electron microscopy, and thermogravimetrical analysis were employed to characterize the as-prepared SnO2/C nanocapsules, and electrochemical tests, including galvanostatic charge-discharge and cyclic voltammetry, were conducted to measure their electrochemical performance. As being employed as an anode material for lithium-ion batteries, the defective curved graphite layers and SnO2 nanoparticles possessed by the SnO2/C nanocapsules can facilitate the electrode-electrolyte contact, promote the electron transfer and Li+ diffusion, and relieve the serve volume change during the charge/discharge cycles. Consequently, the SnO2/C nanocapsules anode exhibits highly stable capacity of up to 1253 mAh g−1 after 500 cycles between 0.005 and 3.0 V vs. Li/Li+ at 0.5 A g−1 and superior high rate performance of 590.4 mAh g−1 at 20 A g−1.