Binder-Free MoO2-MoO3 Nanoarrays as High-Performance Anodes for Li-Ion Batteries

Abstract

To overcome the limitations of commercializing lithium-ion batteries (LIBs), a one-step feasible route is reported to prepare a hybrid matrix of molybdenum oxides (MoO_3-x, x = 0 and 1) thin film anode. In this direction, the electrical conductivity barriers of MoO₃ dielectric are overcome by reinforcing conductive MoO₂ via the chemical vapor deposition (CVD) route. The intermixed array of nanograins and nanoflakes grown over stainless-steel (SS) foil delivers a maximum gravimetric capacitance of 281 F g⁻¹ and a specific capacity of 348 mAh g⁻¹ at 1 A g⁻¹. The synergistic integration of metal oxides facilitates multiple valencies, interfacial structural stability, and abundant ion transport channels to achieve a wider voltage window of 3.50 V. Subsequently, the prepared Li||MoO₂-MoO₃@SS configuration possesses electric double-layer and pseudocapacitive energy storage capacity leading to remarkable specific energy 77.78 Wh kg⁻¹ and excellent specific power 13.75 kW kg⁻¹. The high-rate capacity tests for continuous 1200 charge–discharge cycles disclose retention of ≈88% and ≈100% Coulombic efficiency on a 2-fold enlargement of current density. The longer lifespan and higher rate capacity of nanohybrid anode owing to reversible lithiation/delithiation further recommend its candidacy in developing LIBs for next-generation portable electronics.