High lithium storage of SnO2/Sn@C enabled by a facile, efficient dual-porous architecture

Abstract

SnO2 with a high theoretical capacity has been regarded as a promising candidate for new-generation lithium-ion battery anodes, but challenging as well for the big volumetric variation and poor intrinsic conductivity. To address this challenge, herein, the SnO2 particles containing a small amount of Sn are reduced to the nanoscale and confined in a dual-porous carbon matrix by a relatively facile strategy, and hence exhibits significantly improved electrochemical performance. It is demonstrated that the synergistic effects of SnO2/Sn nanoparticles and dual-porous carbon matrix contribute to fast electrochemical kinetics and enhanced structural stability of the as-prepared SnO2-based composite (SnO2/Sn@p-C). In particular, the dual-porous carbon matrix with two sizes of pores can not only efficiently accommodate the volumetric variation and prevent the aggregation and pulverization of the SnO2/Sn nanoparticles with its big pore confining function, but also promote the ion diffusion and electron transfer by its small pores constructed network conducting open tunnel-like structure. Consequently, the SnO2/Sn@p-C exhibits outstanding lithium storage properties, revealing high capacity of 917.7 mA h g−1 at 200 mA g−1 after 450 cycles as well as 628.9 mA h g−1 at 1000 mA g−1 after 1000 cycles. Thus high-performance makes SnO2/Sn@p-C a promising advanced lithium-ion battery anode.