Disproportionated Tin Oxide and Its Nanocomposite for High‐Performance Lithium‐Ion Battery Anodes

We exploited the unstable characteristics of solid SnO at all temperatures to develop a simple, fast, inexpensive, and scalable method based on high‐energy ball milling to transform SnO into a disproportionated nanocomposite that consists of amorphized Sn and nanocrystalline SnO 2 . In the first step of this process, nanostructured disproportionated SnO (d‐SnO) made up of nanosized Sn and SnO 2 crystallites is produced by ball milling pure SnO powder. The electrochemical performance of the d‐SnO is then enhanced by creating a d‐SnO/C nanocomposite through additional ball milling. This d‐SnO/C nanocomposite was analyzed by various techniques, such as XRD, high‐resolution transmission electron microscopy, and extended X‐ray absorption fine structure analysis, and consists of amorphized Sn (≈sub‐3 nm) and nanocrystalline SnO 2 (≈5–15 nm) within an amorphous carbon matrix. This structure produces excellent electrochemical performances with a high initial energy density (first charge: 892 mA h g −1 or 1436 mA h cm −3 ), a relatively good initial Coulombic efficiency (≈73 %), long cycling stability (above 642 mA h g −1 or 1034 mA h cm −3 over 300 cycles), and a fast rate capability (3 C: 585 mA h g −1 or 942 mA h cm −3 ). Based on these results, we believe that d‐SnO/C nanocomposite electrodes have the potential to create a new area of research in the field of high‐performance Li‐alloy‐based anode materials.