Crystal structure analysis and first principle investigation of F doping in LiFePO4

JOURNAL OF POWER SOURCES

卷:241

Article

Milovic, Milos¹  Jugovic, Dragana¹  Cvjeticanin, Nikola²  Uskokovic, Dragan¹  Milosevic, Aleksandar S.³  Popovic, Zoran S.³  Vukajlovic, Filip R.⁴ 

[1] Inst Tech Sci SASA, Belgrade 11000, Serbia

[2] Univ Belgrade, Fac Phys Chem, Belgrade, Serbia

[3] Univ Belgrade, Vinca Inst Nucl Sci 020, RS-11001 Belgrade, Serbia

[4] Vinca Inst Nucl Sci 020, RS-11001 Belgrade, Serbia

关键词: Lithium iron phosphate (LiFePO4);    Rietveld analysis;    Fluorine doping;    Cathode;    Electronic band structure;   

DOI  :  10.1016/j.jpowsour.2013.04.109

来源: Elsevier

【 摘 要 】

This work presents the synthesis of F-doped LiFePO4/C composite by the specific modification of the recently suggested synthesis procedure based on an aqueous precipitation of precursor material in molten stearic acid, followed by a high temperature treatment. Besides the lattice parameters and the primitive cell volume reductions, compared to the undoped sample synthesized under the same conditions, the Rietveld refinement also shows that fluorine ions preferably occupy specific oxygen sites. Particularly, the best refinement is accomplished when fluorine ions occupy O(2) sites exclusively. By means of up-to-date electronic structure and total energy calculations this experimental finding is theoretically confirmed. Such fluorine doping also produces closing of the gap in the electronic structure and consequently better conductivity properties of the doped compound. In addition, the morphological and electrochemical performances of the synthesized powder are fully characterized. (C) 2013 Elsevier B.V. All rights reserved.

【 授权许可】

Free