Highly reversible Li-ion (de)intercalation to metastable β-MoO_3

摘要

Molybdenum trioxide (MoO_3) has received much attention due to its intriguing physicalproperties and a wide variety of applications including batteries, gas sensors, and catalysts. MoO_3 is oftenfound with two polymorphs: orthorhombic α-MoO_3 with a layered structure and monoclinic β-MoO_3 with aReO_3-derived distorted structure. However, it is difficult to grow metastable β-MoO_3 thin films, especiallywith both single phase and a single orientation. Here we report on epitaxial stabilization and Li-ionelectrochemistry of pure α- and β-MoO_3 films, demonstrating perfect phase control by using pulsed laserdeposition (PLD) and Li-ion electrochemical cells. We found that β-MoO_3 indicated better reversibility anddurability for Li-ion (de)intercalation process compared to α-MoO_3.