The high temperature lithiation behavior of the MoO2 electrode is examined, which is lithiated by one-electron reduction (by
addition reaction) at room temperature. At elevated temperatures, this electrode is lithiated with four-electron reduction by addition
and continued conversion reaction. As a result of four-electron reduction, the initial crystalline MoO2 phase is decomposed into a
nanosized mixture of metallic Mo and Li2O, which is in turn converted to nanosized MoO2 upon forthcoming delithiation. An
interesting feature here is that as-generated nanosized MoO2 is now fully lithiated up to four-electron reduction even at room
temperature. This phenomenon is named thermoelectrochemical activation because the extension from one- to four-electron
reduction is achieved by a simple charge–discharge cycling made at elevated temperatures. The thermoelectrochemically activated
MoO2 electrode delivers a reversible specific capacity that is close to the theoretical four-electron capacity (838 mAh g−1) with
an excellent cycle performance at room temperature.This work was supported by the WCU program through KOSEF
funded by the Ministry of Education, Science and Technology (no.
400-2008-0230). The authors also acknowledge the Research Center
for Energy Conversion and Storage for financial support
