Highly reversible insertion of lithium into MoO2 as an anode material for lithium ion battery

Abstract

MoO2 has gained renewed attention as a safe oxide anode host material for lithium ion insertion because of its high gravimetric/volumetric capacity and highly stable cycling behavior. However, these recent results are completely contrary to previous reports. To confirm that MoO2 is an appropriate anode material as well as further understand lithium ion reactions when inserted into MoO2, we combine electrochemical characterization of MoO2 electrodes and ex situ X-ray diffraction analysis with first principle calculations. Theoretical capacity of the MoO2 electrode (∼209 mAh g−1) and stable capacity retention up to 100 cycles are simultaneously attained using a proper particle size and type of binder. Ex situ XRD analysis with first principle calculations of the phase transformation of MoO2 electrodes shows that MoO2 undergoes reversible structural changes upon lithiation and subsequent delithiation, clearly demonstrating that nanostructured MoO2 can be used as an anode material for highly reliable lithium ion batteries.