In-Situ X-Ray Diffraction Study of the Li-Alloying Electrochemical Process in a Tin-Carbon Nanocomposite Electrode

摘要

A high capacity lithium alloying composite in which 10-50 nm size tin (Sn) particles are trapped within a carbon matrix is here deeply studied by employing in-situ X-ray diffraction during the electrochemical reaction in lithium cell. The reversibility of the process is evidenced by the vanishing and the re-appearing of the crystallographic peaks associated with the Sn metal, while the signatures of few Li-Sn alloys are identified as the intermediate reaction products. These clear evidences, in addition to the electrochemical charge-discharge tests run using the tin carbon composite as working electrode in the lithium cell, demonstrate the high reversibility of the process, and hence the valid role of the tin carbon composite as high performance electrode for advanced lithium ion batteries.