Walnut-like MoO2 with interconnected skeleton and opened muti-channel for fast sodium storage

Molybdenum dioxide (MoO2) has attracted lots of theoretical interest as an anode material for sodium ion batteries (SIBs) due to its high theoretical capacity (836 mA h g-1) and metallic electrical conductivity (1.9 × 102 S cm-1). The insertion reaction, forming Na0.98MoO2 and the reversible conversion reaction, forming Mo and Na2O from Na0.98MoO2 contribute capacities of 209 and 627 mA h g-1, respectively, the latter occupies 75% of the totally theoretical capacity. However, intrinsic slow kinetics in bulk MoO2 severely restricts the redox conversion reaction. In the present work, a walnut-like MoO2 architecture (W-MoO2) with opened multi-channel and interconnected skeleton was prepared in a tube furnace, providing an interconnected ion/electron dual-pathway, which effectively facilitates Na+ diffusion and reduces the internal resistance of the cells. The W-MoO2 anode demonstrates an enhanced reversible sodium storage capacity of 354.7 mA h g-1 at 0.5 A g-1.