Reducing hydrated protons co-intercalation to enhance cycling stability of CuV2O5 nanobelts: a new anode material for aqueous lithium ion batteries

Abstract

The aqueous-based lithium ion batteries have attracted considerable interest because of their high safety, low cost and environmental friendliness for rechargeable energy storage. Herein, a new anode material, uniform CuV₂O₅ nanobelts, was prepared through a facile hydrothermal route for the first time. The detailed structures and chemical state of the as-obtained CuV₂O₅ were investigated and the formation mechanism was proposed. The CuV₂O₅ nanobelts show high electrical conductivity, which could improve their Li-ion insertion/extraction kinetics. The ex situ XRD, XPS and TG study of the lithiated electrode demonstrated that a considerable amount of hydrated protons were co-intercalated into the layer space of CuV₂O₅ during the charge process, finally leading to irreversible phase collapse with some amorphization. The CuV₂O₅ anode exhibited the best cycle performance at pH ∼8.5, indicating that reducing the co-intercalation of hydrated protons would be an effective way to improve the cycling stability of similar layered vanadates.