Storage of Lithium-Ion by Phase Engineered MoO 3 Homojunctions.

With high theoretical specific capacity, the low-cost MoO 3 is known to be a promising anode for lithium-ion batteries. However, low electronic conductivity and sluggish reaction kinetics have limited its ability for lithium ion storage. To improve this, the phase engineering approach is used to fabricate orthorhombic/monoclinic MoO 3 (α/h-MoO 3 ) homojunctions. The α/h-MoO 3 is found to have excessive hetero-phase interface. This not only creates more active sites in the MoO 3 for Li + storage, it regulates local coordination environment and electronic structure, thus inducing a built-in electric field for boosting electron/ion transport. In using α/h-MoO 3 , higher capacity (1094 mAh g -1 at 0.1 A g -1 ) and rate performance (406 mAh g -1 at 5.0 A g -1 ) are obtained than when using only the single phase h-MoO 3 or α-MoO 3 . This work provides an option to use α/h-MoO 3 hetero-phase homojunction in LIBs.