Exfoliated Graphene Oxide/MoO2 Composites as Anode Materials in Lithium-Ion Batteries: An Insight into Intercalation of Li and Conversion Mechanism of MoO2

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• 作者：Shaikshavali Petnikota ; Keefe Wayne Teo ; Luo Chen ; Amos Sim ; Sandeep Kumar Marka ; M. V. Reddy ; V. V. S. S. Srikanth ; S. Adams ; B.V.R. Chowdari
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2016
• 出版时间：May 4, 2016
• 年：2016
• 卷：8
• 期：17
• 页码：10884-10896
• 全文大小：931K
• 年卷期：0
• ISSN：1944-8252

文摘

Exfoliated graphene oxide (EG)/MoOb>2b> composites are synthesized by a simple solid-state graphenothermal reduction method. Graphene oxide (GO) is used as a reducing agent to reduce MoOb>3b> and as a source for EG. The formation of different submicron sized morphologies such as spheres, rods, flowers, etc., of monoclinic MoOb>2b> on EG surfaces is confirmed by complementary characterization techniques. As-synthesized EG/MoOb>2b> composite with a higher weight percentage of EG performed excellently as an anode material in lithium-ion batteries. The galvanostatic cycling studies aided with postcycling cyclic voltammetry and galvanostatic intermittent titrations followed by ex situ structural studies clearly indicate that Li intercalation into MoOb>2b> is transformed into conversion upon aging at low current densities while intercalation mechanism is preferably taking place at higher current rates. The intercalation mechanism is found to be promising for steady-state capacity throughout the cycling because of excess graphene and higher current density even in the operating voltage window of 0.005–3.0 V in which MoOb>2b> undergoes conversion below 0.8 V.