Carbon shelled porous SnO2-δ nanosheet arrays as advanced anodes for lithium-ion batteries

Abstract

Although SnO2 is theoretically a high capacity anode material for lithium-ion batteries, it suffers from poor cycle performance and poor rate capability due to structural instability and sluggish electrode kinetics. To mitigate these problems, here, an oxygen-deficient SnO2-δ/C composite with rationally designed nanoarchitecure comprising carbon shelled porous SnO2-δ nanosheet arrays is prepared as anode for lithium-ion batteries. It is found that crystalline and amorphous domains coexist in the SnO2-δ phase, which is beneficial for improved structural stability and enhanced Li+ diffusion. The as-prepared porous SnO2-δ/C nanosheet arrays can deliver a large reversible specific capacity of 1378.6 mA h g−1 with a high initial Coulombic efficiency of about 74.3% at a current density of 0.1 A g−1. In addition to large reversible capacity, the porous SnO2-δ/C nanosheet arrays also exhibit superior rate performance and cycle performance, outperforming those of SnO2, porous SnO2, and SnO2-δ/C nanosheet arrays, demonstrating robust structural stability, high reversibility, and fast charge transport for the rational nanoarchitecture design. Finally, a full cell consisting of porous SnO2-δ/C nanosheet arrays as anode and LiMn2O4 nanosheet arrays as cathode is constructed and exhibits promising battery performance, demonstrating the potential application of porous SnO2-δ/C nanosheet arrays in high-performance lithium-ion batteries.