Blend formed by oxygen deficient MoO3-δ oxides as lithium-insertion compounds

JOURNAL OF ALLOYS AND COMPOUNDS

卷:686

Article

Hashem, A. M.^1,2  Abbas, S. M.³  Abdel-Ghany, A. E.¹  Eid, A. E.¹  Abdel-Khalek, A. A.³  Indris, S.²  Ehrenberg, H.²  Mauger, A.⁴  Julien, C. M.⁵ 

[1] Natl Res Ctr, Dept Inorgan Chem, 33 El Bohouth St,El Tahrir St, Dokki Giza 12622, Egypt

[2] KIT, IAM ESS, Hermann von Helmholtz Pl 1, D-76344 Eggenstein Leopoldshafen, Germany

[3] Beni Suef Univ, Fac Sci, Dept Chem, Bani Suwayf 62111, Egypt

[4] Univ Paris 06, Sorbonne Univ, PHENIX, UMR 8234, 4 Pl Jussieu, F-75005 Paris, France

[5] Univ Paris 06, Sorbonne Univ, IMPMC, 4 Pl Jussieu, F-75005 Paris, France

关键词: Molybdenum oxides;    Oxygen deficiency;    Sol-gel synthesis;    Blend;    Lithium-insertion compounds;   

DOI  :  10.1016/j.jallcom.2016.06.043

来源: Elsevier

【 摘 要 】

Oxygen deficient MoxOy 200 nm-thick particles were synthesized by a citrate sol-gel method using ammonium heptamolybdate tetrahydrate as a source of Mo and heat treated with a small fraction of zirconia under reducing atmosphere. The samples were investigated by X-ray powder diffraction (XRD), thermal gravimetric analysis (TGA), scanning electron microscope (SEM) and Raman spectroscopy (RS). The structural analyses show that the composite is a blend formed by layered alpha-MoO3, orthorhombic oxygen deficient phases MoO3 delta with delta = 0.25 (gamma-Mo4O11) and alpha-ZrMo2O8. The insertion of lithium into the lattice was performed by electrochemical method. Redox peaks were observed for the MoO3-delta composite attributed to distinct Li+ ion insertion/extraction reactions in the MoO3 and Mo4O11 hosts. The cyclic performance revealed improved reversibility, rate capability, and electrochemical stability of the ZrMo2O8-decorated composite with respect to the bare molybdenum oxides. At C/10 rate, the composite delivered a stable reversible capacity of 135 mAh g(-1) after the 50th cycle. At a rate of 2C the reversible capacity is maintained at 118 mAh g(-1), approximately twice the capacity observed for the MoO3 particles alone. (C) 2016 Elsevier B.V. All rights reserved.

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