High Capacity and Reversibility of Oxygen‐Vacancy‐Controlled MoO₃ on Cu in Li‐Ion Batteries: Unveiling Storage Mechanism in Binder‐Free MoO_3−x Anodes

Abstract

MoO3 has great potential as an electrode for lithium‐ion batteries due to its unique layered structure that can host Li+. Despite high theoretical capacity (≈1117 mAh g−1), MoO3 is not widely used simply because of poor rate capability due to lower electronic conductivity and severe pulverization. The Li‐storage mechanism in MoO3 is also still unclear. Herein, oxygen‐vacancy‐controlled MoO3 is used without any additional binders and conductive materials to directly examine the Li‐storage mechanism on MoO3−x. Li‐storage capacity based on the reversible formation/decomposition of solid‐electrolyte interphase (SEI) films and the transformation of MoO3−x to amorphous Li2MoO3 is demonstrated. The surfaces of MoO3−x are conjugated with Cu2O nanoparticles via annealing at 200 °C. Cu2O acts as an effective catalyst for the formation of SEI films and the reversible reaction of MoO3−x with Li+ ions. As a result, Cu2O@MoO3−x exhibits a charge capacity of 1100 mAh g−1 after the second cycle and maintains a high reversible capacity, whereas MoO3−x exhibits a charge capacity of 900 mAh g−1 and fades to 590 mAh g−1 after 100 cycles at 1 A g−1.

In Situ Construction of Zn2Mo3O8/ZnO Hierarchical Nanosheets on Graphene as Advanced Anode Materials for Lithium-Ion Batteries

“…0.2 V, corresponding to the alloying reaction of Zn and lithium, and further Li + intercalation into rGO sheets. ,, In the reverse charge process, several anodic peaks below 0.75 V resulted from the multistep dealloying process of the Zn–Li alloy phase and the Li + extraction from rGO sheets. ,, In addition, two anodic peaks occurred at ca. 1.31 and 1.99 V, corresponding to the reoxidation of Zn and Mo. , During the 2nd cathodic scan, a new peak appeared at around 1.88 V, which was correlated with the addition-type reaction of MoO 3 produced during the 1st cycle because of its higher lithiation potential than MoO 2 (1.83 V for MoO 3 and 1.6 for MoO 2 ) but lower activation barrier. − The two cathodic peaks at ca. 0.65 and 0.37 V shifted toward a higher potential of ca.…”

Synthesis and photothermal performance of non-stoichiometric molybdenum oxide (MoO3−x) prepared by gamma radiation

“…This suggests a gradual MoO 3 exfoliation process driven by Coulomb forces between charges at its lamellar structure. 27–29…”

Tunable oxygen deficient in MoO 3 ‐x / MoO 2 heterostructure for enhanced lithium storage properties

“…9,10 Benefiting from the merits of high theoretical specific capacity (≈1117 mAh g À1 , second highest of all conversion reaction based TMOs), low cost, chemical stability, and environment friendly, molybdenum trioxides (MoO 3 ) has attracted numerous attention and became a promising anode component in LIBs. 11 However, the poor conductivity and large volume change during cycling result in distinctive pulverization. The orthorhombic α-MoO 3 shows a stable layered crystal structure of corner and edge shared MoO 6 octahedra, leading to the twodimensional double-layered structure of MoO 3 in which the MoO 6 layers are linked by weak van der Waals interactions.…”