Controllable construction of interconnected SnOx/N-doped carbon/carbon composite for enhanced-performance lithium-ion batteries anodes

Abstract

Tin-based materials have been considered as promising anode materials for their high theoretical capacities in rechargeable lithium ion batteries. However, the large volume variation during repeated lithiation/delithiation processes, leads to aggregation and pulverization of active materials, which limits their practical application. Herein, a facile and effective strategy was designed to construct interconnected porous SnOx/N-doped carbon framework, using Sn(IV)-containing polypyrrole as sacrificial template/precursor followed by depositing carbonaceous species via ethanol steam reforming process. Benefiting from the synergistic effects between ultrafine SnO2 and Sn nanocrystals, porous N-doped carbon and carbon matrices derived from polypyrrole and ethanol, respectively, the composite exhibits large reversible capacity of 728.6 mAh g−1 after 140 cycles at 100 mA g−1, and a long-term cycling performance of 435 mAh g−1 after 500 cycles even at 1000 mA g−1. The remarkable high electrochemical performance, together with the scalable production and low-cost starting materials, will advance the promising application of Sn-based composite to next generation rechargeable batteries.