A Water Based Synthesis of Ultrathin Hydrated Vanadium Pentoxide Nanosheets for Lithium Battery Application: Free Standing Electrodes or Conventionally Casted Electrodes?. (20th October 2017)

• Record Type: Journal Article
• Authors: Etman, Ahmed S.; Inge, A. Ken; Jiaru, Xu; Younesi, Reza; Edström, Kristina; Sun, Junliang
• Is Part Of: Electrochimica acta. Volume 252(2017)
• Page Start: 254
• Page End: 260
• Publication Date: 2017-10-20
• Subjects: V2O5·nH2O nanosheets -- lithium battery -- free standing -- water based synthesis; Electrochemistry -- Periodicals; Electrochemistry, Industrial -- Periodicals; 541.37
• DOI: 10.1016/j.electacta.2017.08.137
• Languages: English
• ISSNs: 0013-4686

Abstract

Graphical abstract: Ultrathin V2 O5 ·nH2 O nanosheets are prepared via a facile one-step water based exfoliation technique. Operando XRD is used to track the structural changes during the exfoliation process. A composite material from the V2 O5 ·nH2 O nanosheets and 10% of multi-walled carbon nanotube (MW-CNT) is fabricated and shows a promising capacity and rate capabilities for lithium battery application. Highlights: Facile water based synthesis of V2 O5 ·nH2 O nanosheets. Operando XRD study to follow up the synthesis of V2 O5 ·nH2 O nanosheets. Simple method to fabricate flexible and free standing electrodes (FSE). Significant improvement in the accessible capacity for lithium-ion intercalation in FSE. Abstract: Ultrathin hydrated vanadium pentoxide (V2 O5 ·nH2 O) nanosheets are fabricated via a water based exfoliation technique. The exfoliation process involves reflux of the precursor, 1:4 mixture of VO2 and V2 O5, in water at 80 °C for 24 h. Operando and ex situ X-ray diffraction (XRD) studies are conducted to follow the structural changes during the exfoliation process. The chemical and thermal analyses suggest that the molecular formula of the nanosheet is H 0.2 V 1.8 V V 0.2 IV O 5 ⋅ 0.5 H 2 O . The V2 O5 ·nH2 O nanosheets are mixed with 10% of multi-walled carbon nanotube (MW-CNT) to form a composite material assigned as (VOx-CNT). Free standing electrodes (FSE) and conventionally casted electrodes (CCE) of VOx-CNT are fabricated and then tested as a positive electrode material for lithium batteries. The FSE shows reversible capacities of 300 and 97 mAhg -1 at current densities of 10 and 200 mAhg -1, respectively. This is better than earlier reports for free-standing electrodes. The CCE delivers discharge capacities of 175 and 93 mAhg -1 at current densities of 10 and 200 mAhg -1, respectively.