Carbon coated porous SnO₂ nanosheet arrays on carbon cloth towards enhanced lithium storage performance

SnO₂ is viewed as a developing anode material due to high theoretical capacity of 1494 mAh g⁻¹. However, the volume change during the lithiation/delithiation causes the active material aggregation and cracking, which lead to a rapid capacity fade. Meanwhile, the poor electrical conductivity of SnO₂ is another weakness which deteriorates the electrochemical performance. Herein, to overcome these shortcomings, the self-supported carbon coated porous SnO₂ nanosheet arrays (C@SnO₂@CC) are prepared by CO₂ assisted anneal strategy. Porous SnO₂ nanosheet arrays can provide more active sites and large specific surface area for electrochemical reaction, and the nanostructure shortens electronic and ionic transport length. Moreover, the carbon coating layer not only enhances the electrical conductivity but also buffers the volume expansion of SnO₂ upon lithiation. Consequently, the porous C@SnO₂@CC electrode delivers a high specific capacity of 1096.6 mAh g⁻¹ and remains at 975.0 mAh g⁻¹ after 120 cycles at 1 A g⁻¹.