Facile\nSynthesis of a Tin Oxide-Carbon Composite Lithium-Ion Battery Anode\nwith High Capacity Retention

Abstract

A tin oxide-carbon\ncomposite (SnO_<i>x</i>-C) was fabricated as a\ncandidate for use as an anode in lithium-ion batteries through the\npyrolysis of a ditin citrate precursor. The simultaneous formation\nof tin oxide and semigraphitized carbon via a facile, solid-state\npyrolysis yielded a composite containing tin oxide nanocrystals surrounded\nby a framework of flexible, porous carbon. Fabrication of tin oxide\nnanoparticles encased in semigraphitized carbon, led to the enhanced\nreversibility of Li₂O formation, prevented the aggregation\nof tin during lithiation and suppressed particle fracturing during\ncycling. The resulting SnO_<i>x</i>-C composite\nexhibited an exceptional electrochemical performance as an anode material\ncandidate for lithium-ion batteries with an initial capacity of 541\nmAh g^–1 and 80.6% capacity retention over 400 cycles\nat a high current density of 900 mA g^–1 (1C). Lower\ncurrent density studies [450 mA g^–1 (C/2)] have\nshown the material to have an initial capacity of 667 mAh g^–1 with 88.7% capacity retention over 400 cycles, whereas a current\ndensity of 180 mA g^–1 (C/5) gave a capacity of 710\nmAh g^–1 with 88.8% capacity retention over 400 cycles.\nThrough a systematic analysis involving X-ray diffraction, X-ray photoelectron\nspectroscopy, Raman spectroscopy, cyclic voltammetry, cross-sectional\nanalysis, and post-mortem analysis, we examine how the architecture\nand composition of the SnO_<i>x</i>-C material\nleads to a high capacity retention tin oxide-carbon composite anode\nfor lithium-ion batteries.