Storage of Lithium-Ion by Phase Engineered MoO₃ Homojunctions

With high theoretical specific capacity, the low-cost MoO₃ 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 MoO₃ (α/h-MoO₃) homojunctions. The α/h-MoO₃ is found to have excessive hetero-phase interface. This not only creates more active sites in the MoO₃ 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-MoO₃, 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-MoO₃ or α-MoO₃. This work provides an option to use α/h-MoO₃ hetero-phase homojunction in LIBs.