A Composite of Nb2O5 and MoO2 as a High‐Capacity High‐Rate Anode Material for Lithium‐Ion Batteries

A high-capacity high-rate composite: Hydrothermal crystallisation under mild conditions yields a composite of niobium and molybdenum oxides that is homogeneous on the submicron scale: the material shows lithium storage with high rate capability and stability and offers a significant advantage of operating at a higher cycling rate than conventional composites of the component oxides.

Abstract

A composite of Nb₂O₅ and MoO₂ was synthesised using a hydrothermal reaction (225 °C) followed by a short heat-treatment step (600 °C) to achieve a high-capacity, high-rate anode for lithium-ion battery applications. The composite was shown via powder X-ray diffraction and electron microscopy to be an intimate mix of individual oxide particles rather than an atomically mixed oxide material, and shown by X-ray fluorescence spectroscopy (XRF) to contain a 45 : 55 ratio of Nb : Mo. This material is demonstrated to show notable rate capability in lithium (Li) half-cell cycling and rate tests. When cycled at 100 °C the material achieved over 100 mAh g⁻¹ even after 400 cycles and shows a stable reversible capacity of 514 mAh g⁻¹ (at 1 C), realising its theoretical capacity. The composite shows electrochemical results comparable to Nb₂O₅:C composites yet achieves far higher capacities at low-rate due to the MoO₂ content.

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