In situ XAS of Molybdenum Dichalcogenides as Li-Ion Battery Anodes

摘要

Due to high specific capacity for lithiation, molybdenum dichalcogenides such as MoO2 and MoS2 are potential replacements for graphite anodes in Li-ion batteries. However, in bulk form these materials exhibit poor rate capability and lose capacity with each cycle. While the performance can be improved by changes to morphology, the details of the lithium intercalation mechanism are not fully understood.;In this work, X-ray absorption spectroscopy (XAS) is employed to investigate this mechanism, including X-ray absorption near-edge spectroscopy (XANES) and X-ray absorption fine-structure spectroscopy (XAFS). For MoS 2, modeling of the local structure supports the metallic conversion reaction model by the second lithiation.