초록 |
We demonstrate a mesoporous molybdenum dioxide material with abnormal lithium storage site, which exhibits a discharge capacity of 1814 mAh g-1 for the first cycle, more than twice than its theoretical value, and maintains its initial capacity after 50 cycles. Contrary to previous reports, we find that a mechanism for the high and reversible lithium-storage capacity of the mesoporous molybdenum dioxide electrode is not based on conversion reaction. Insight into the electrochemical results, obtained by in situ X-ray absorption, scanning transmission electron microscopy analysis combined with electron energy loss spectroscopy and computational modeling, indicates that the nano-scale pore engineering of this transition metal oxide enables an unexpected electrochemical mass storage reaction mechanism, and provides a promising paradigm for the design of cation storage materials for battery systems. |