Effects of Nb-doped on the structure and electrochemical performance of LiFePO{sub 4}/C composites
- Hebei Key Laboratory of Applied Chemistry, College of Environmental and Chemical Engineering, Yanshan University, Qinhuangdao 066004 (China)
The olivine-type niobium doping Li{sub 1−x}Nb{sub x}FePO{sub 4}/C (x=0, 0.005, 0.010, 0.015, 0.025) cathode materials were synthesized via a two-step ball milling solid state reaction. The effects of Nb doping were charactered by X-ray diffraction (XRD), field-emission scanning electron microscopy (FE-SEM), galvanostatic intermittent titration technique (GITT), cyclic voltammetry (CV), electrochemical impedance spectra (EIS) and galvanostatic charge–discharge. It is found that Nb doping enlarges the interplanar distance of crystal plane parallel to [0 1 0] direction in LiFePO{sub 4}. In other words, it widens the one dimensional diffusion channels of Li{sup +} along the [0 1 0] direction. Electrochemical test results indicate that the Li{sub 0.99}Nb{sub 0.01}FePO{sub 4}/C composite exhibits the best electrochemical performance with initial special discharge capacity of 139.3 mA h g{sup −1} at 1 C rate. The present synthesis route is promising in making the solid state reaction method more practical for preparation of the LiFePO{sub 4} material. - Graphical abstract: The proper amount of Nb doping widens the one dimensional diffusion channels of Li{sup +} along the [0 1 0] direction. Display Omitted - Highlights: • The Nb doping LiFePO{sub 4}/C is prepared by a facile two-step ball milling solid state reaction. • The sample possesses the better high-rate performance. • The tap density of Li{sub 0.99}Nb{sub 0.01}FePO{sub 4}/C sample is 1.76 g cm{sup −3}.
- OSTI ID:
- 22274220
- Journal Information:
- Journal of Solid State Chemistry, Vol. 210, Issue 1; Other Information: Copyright (c) 2013 Elsevier Science B.V., Amsterdam, The Netherlands, All rights reserved.; Country of input: International Atomic Energy Agency (IAEA); ISSN 0022-4596
- Country of Publication:
- United States
- Language:
- English
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