Facile preparation of four SnOx-C hybrids with superior electrochemical performance for lithium-ion batteries

摘要

SnOx is considered as a promising anode candidate for lithium-ion batteries, but suffers from the low electrical conductivity and severe volume expansion during cycling. To solve these issues, we develop a simple and facile process of incipient wetness impregnation followed by pyrolysis gel molecules to prepare SnOx/mesoporous carbon nanofiber arrays, SnOx/graphene, SnOx/carbon nanotubes and SnOx/three-dimensionally ordered macroporous carbon materials. Notably, SnOx nanoparticles about 5 nm are prepared by a nonaqueous sol-gel method. We also explore the effect of different morphologies and pore structures of four carbon substrates on the electrochemical performance of the composites. Benefiting from the small size of SnOx nanoparticles and the synergistic effect between SnOx and the different carbon matrix materials, SnOx-Carbon electrode materials display excellent rate capability and cycle stability. SnOx/mesoporous carbon nanofiber arrays exhibits the best rate (522 mA h g(-1) at 2000 mA g(-1)) and cycling performances (1327 mA h g(-1) after 200 cycles at 100 mAg(-1)). The superior electrochemical performance, facile synthesized method and low cost of the Sn-based materials exhibit promising application for SnOx/mesoporous carbon nanofiber arrays as anode materials for next-generation lithium-ion batteries. Furthermore, the ex situ X-ray photoelectron spectroscopy studies on this electrode material under different states suggest that the Sn and Li2O could reversibly react to form SnOx during the charging process. (C) 2018 Elsevier Ltd. All rights reserved.