High capacity tin-iron oxide-carbon nanostructured anode for advanced lithium ion battery

A novel nanostructured Sn-Fe2O3-C anode material, prepared by high-energy ball milling, is here originally presented. The anode benefits from a unique morphology consisting in Fe2O3 and Sn active nanoparticles embedded in a conductive buffer carbon matrix of micrometric size. Furthermore, the Sn metal particles, revealed as amorphous according to X-ray diffraction measurement, show a size lower than 10 nm by transmission electron microscopy. The optimal combination of nano-scale active materials and micrometric electrode configuration of the Sn-Fe2O3-C anode reflects into remarkable electrochemical performances in lithium cell, with specific capacity content higher than 900 mAh g−1 at 1C rate (810 mA g−1) and coulombic efficiency approaching 100% for 100 cycles. The anode, based on a combination of lithium conversion, alloying and intercalation reactions, exhibits exceptional rate-capability, stably delivering more than 400 mAh g−1 at the very high current density of 4 A g−1. In order to fully confirm the suitability of the developed Sn-Fe2O3-C material as anode for lithium ion battery, the electrode is preliminarily studied in combination with a high voltage LiNi0.5Mn1.5O4 cathode in a full cell stably and efficiently operating with a 3.7 V working voltage and a capacity exceeding 100 mAh g−1.