Enhanced nanoscale conduction capability of a MoO₂/Graphene composite for high performance anodes in lithium ion batteries

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• 作者：Akkisetty Bhaskar ; Melepurath Deepa ; T.N. Rao ; U.V. Varadaraju
• 关键词：Molybdenum dioxide ; Graphene ; Lithium ion batteries ; Conducting atomic force microscopy ; Anode
• 刊名：Journal of Power Sources
• 出版年：2012
• 出版时间：15 October, 2012
• 年：2012
• 卷：216
• 期：Complete
• 页码：169-178
• 全文大小：2337 K

文摘

A MoO₂/Graphene composite as a high performance anode for Li ion batteries is synthesized by a one pot in-situ low temperature solution phase reduction method. Electron microscopy and Raman spectroscopy results confirm that 2D graphene layers entrap MoO₂ nanoparticles homogeneously in the composite. X-ray photoelectron spectroscopy shows the presence of oxygen functionalities on graphene, which allows intimate contact between MoO₂ nanoparticles and the graphene. Conductive atomic force microscopy reveals an extraordinarily high nanoscale electronic conductivity for MoO₂/Graphene, greater by 8 orders of magnitude in comparison to bulk MoO₂. The layered nanostructure and the conductive matrix provide uninhibited conducting pathways for fast charge transfer and transport between the oxide nanoparticles and graphene which are responsible for the high rate capability, a large lithium ion capacity of 770?mAh?g^?1, and an excellent cycling stability (550?mAh?g^?1 reversible capacity retained even after 1000 cycles!) at a current density of 540?mA?g^?1, thereby rendering it to be superior to previously reported values for neat MoO₂ or MoO₂/Graphene composite. Impedance analyses demonstrate a lowered interfacial resistance for the composite in comparison to neat MoO₂. Our results demonstrate the enormous promise that MoO₂/Graphene holds for practical Li-ion batteries.