Characterization of Sn₄P₃-Carbon Composite Films for Lithium-Ion Battery Anode Fabricated by Aerosol Deposition

We fabricated tin phosphide-carbon (Sn₄P₃/C) composite film by aerosol deposition (AD) and investigated its electrochemical performance for a lithium-ion battery anode. Sn₄P₃/C composite powders prepared by a ball milling was used as raw material and deposited onto a stainless steel substrate to form the composite film via impact consolidation. The Sn₄P₃/C composite film fabricated by AD showed much better electrochemical performance than the Sn₄P₃ film without complexing carbon. Although both films showed initial discharge (Li⁺ extraction) capacities of approximately 1000 mAh g^-1, Sn₄P₃/C films retained higher reversible capacity above 700 mAh g^-1 after 100 cycles of charge and discharge processes while the capacity of Sn₄P₃ film rapidly degraded with cycling. In addition, by controlling the potential window in galvanostatic testing, Sn₄P₃/C composite film retained the reversible capacity of 380 mAh g^-1 even after 400 cycles. The complexed carbon works not only as a buffer to suppress the collapse of electrodes by large volume change of Sn₄P₃ in charge and discharge reactions but also as an electronic conduction path among the atomized active material particles in the film.