Enhanced electrochemical performance of graphene modified LiFePO$_4$ as a cathode material for lithium ion batteries

ORAL

Abstract

We synthesized LiFePO$_4$/graphene nano-composites using a sol-gel method by adding water dispersed graphene oxide to the LiFePO$_4$ precursors during the synthesis. The graphene oxide was subsequently reduced to graphene by annealing the composite which was confirmed by Raman spectroscopy and X-ray Photoelectron spectroscopy. The electronic conductivity of the composite was found to be six orders of magnitude higher than that of pure LiFePO$_4$ Scanning Electron microscopy and Transmission electron microscopy images show LiFePO$_4$ particles are wrapped in uniformly distributed graphene sheets throughout the material forming a three dimensional conducting network. At low currents, (C/3), the capacity of the composite cathode reaches 160 mAh/g, which is very close to the theoretical limit. More significantly, the graphene wrapped LiFePO$_4$ shows a dramatically improved rate capability up to 27C, and excellent charge-discharge cycle stability over 500 stable cycles as compared to the pure LiFePO$_4$.

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Authors

  • Kulwinder Singh Dhindsa

    Wayne State University, Detroit, Michigan, USA

  • Balaji Prasad Mandal

    Wayne State University, Detroit, Michigan, USA

  • Ming-Wei Lin

    Wayne State University, Detroit, Michigan, USA

  • Maryam Nazri

    Wayne State University, Applied Sciences Inc., Wayne State University, Detroit, Michigan, USA

  • Gholam Abbas Nazri

    Wayne State University, Wayne State University, Detroit, Michigan, USA

  • Vaman M. Naik

    University of Michigan, Dearborn, Michigan, USA

  • Prem Vaishnava

    Kettering University, Kettering University, Flint, Michigan

  • Ratna Naik

    Department of Physics and Astronomy, Wayne State University, Detroit, Michigan, Wayne State University, Wayne State University, Detroit, Michigan, USA

  • Zhixian Zhou

    Wayne State University, Detroit, Michigan, USA