Superior Hybrid Cathode Material Containing Lithium-Excess Layered Material and Graphene for Lithium-Ion Batteries

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• 作者：Ke-Cheng Jiang ; Xing-Long Wu ; Ya-Xia Yin ; Jong-Sook Lee ; Jaekook Kim ; Yu-Guo Guo
• 刊名：ACS Applied Materials & Interfaces
• 出版年：2012
• 出版时间：September 26, 2012
• 年：2012
• 卷：4
• 期：9
• 页码：4858-4863
• 全文大小：386K
• 年卷期：v.4,no.9(September 26, 2012)
• ISSN：1944-8252

文摘

Graphene-wrapped lithium-excess layered hybrid materials (Li₂MnO₃路LiMO₂, M = Mn, Ni, Co, hereafter abbreviated as LMNCO) have been synthesized and investigated as cathode materials for lithium-ion batteries. Cyclic voltammetry measurement shows a significant reduction of the reaction overpotential in benefit of the graphene conducting framework. The electrochemical impedance spectroscopy results reveal that the graphene can greatly reduce the cell resistance, especially the charge transfer resistance. Our investigation demonstrates that the graphene conducting framework can efficiently alleviate the polarization of pristine LMNCO material leading to an outstanding enhancement in cell performance and cycling stability. The superior electrochemical properties support the fine hybrid structure design by enwrapping active materials in graphene nanosheets for high-capacity and high-rate cathode materials.

Keywords:

lithium-ion batteries; hybrid materials; cathode; lithium-excess layered materials; graphene