Constructing MoO₂ Porous Architectures Using Graphene Oxide Flexible Supports for Lithium Ion Battery Anodes

Graphene oxide flexibly supported MoO₂ porous architectures (MoO₂/GO) by decomposition of the prepared ammonium molybdate/GO preforms is fabricated. Focused ion beam microscope analysis shows that the inside structures of the architectures strongly depend on the percentages of the GO used as flexible supports: micrometer scale MoO₂ particulates growing on the GO (micrometer MoO₂/GO), 3D honeycomb-like nanoarchitectures (MoO₂/GO nanohoneycomb), and layered MoO₂/GO architectures are achieved at the percentage of GO at 4.3, 15.2, and 20.8 wt%, respectively. The lithium storage performance of the MoO₂/GO architectures strongly depends on their inside structures. At the current density of 100 mA g⁻¹, the capacities of the micrometer MoO₂/GO, MoO₂/GO nanohoneycomb, and layered MoO₂/GO remain at 901, 1127, and 967 mAh g⁻¹ after 100 cycles. The average coulombic efficiencies of micrometer MoO₂/GO, MoO₂/GO nanohoneycomb, and layered MoO₂/GO electrodes are 97.6%, 99.3%, and 99.0%. Moreover, the rate performance shows even cycled at a high current density of 5000 mA g⁻¹, the MoO₂/GO nanohoneycomb can deliver the capacity as high as 461 mAh g⁻¹. The MoO₂/GO nanohoneycomb exhibits best performance attributed to its unique nanohoneycomb structure constructed with ultrafine MoO₂ fixed on the GO flexible supports.