Electrochemical intercalation of lithium into vanadium pentaoxide: an in situ X-ray absorption study

An X-ray absorption study at the vanadium K edge has been performed on the LixV2O5(x= 0–0.78) system. For this, an electrochemical cell has been designed in order to allow in situ measurements. The spectra were recorded every 0.03 Li (mol V2O5)–1 using the same sample left in the X-ray beam. The study of the XANES spectra shows that the vanadium environment becomes more symmetrical as the intercalation progresses. Furthermore, the Natoli rule applied to these spectra reveals a mean lengthening of the vanadium–oxygen bond of 0.05 A. This result is confirmed by the EXAFS study. This EXAFS study also reveals a shortening of the vanadium–vanadium bond of 0.08 A. The results are interpreted as being due to the partial reduction of vanadium(V) to vanadium(IV), and its move from its initial position in a square pyramid towards the basal oxygen plane of the pyramid.

[1]  D. Tryk,et al.  Electrochemical Insertion of Lithium into Pyrite from Nonaqueous Electrolytes at Room Temperature: An in Situ Fe K-Edge X-ray Absorption Fine Structure Study , 1995 .

[2]  B. Scrosati,et al.  Ambient Temperature Lithium Polymer Rocking‐Chair Batteries , 1994 .

[3]  E. Stern,et al.  Number of relevant independent points in x-ray-absorption fine-structure spectra. , 1993, Physical review. B, Condensed matter.

[4]  Dominique Guyomard,et al.  The Li1+xMn2O4/C rocking-chair system: a review , 1993 .

[5]  B. Poumellec,et al.  Polarized xanes and exafs at the V K-edge of VOPO4 · 2H2O gel, comparison with the V K-edge in V2O5 xerogel , 1993 .

[6]  A. Jacobson,et al.  Nickel K-edge x-ray absorption fine structure of lithium nickel oxides , 1993 .

[7]  G. Ouvrard,et al.  Transition metal displacement in cathodic host structures upon lithium intercalation , 1993 .

[8]  Bruno Scrosati,et al.  Lithium Rocking Chair Batteries: An Old Concept? , 1992 .

[9]  G. Ouvrard,et al.  EXAFS study of lithium-intercalated iron thiophosphate , 1991 .

[10]  G. Ouvrard,et al.  X-ray absorption study of lithium intercalated thiophosphate NiPS3 , 1990 .

[11]  R. Messina,et al.  X-ray diffraction and X-ray absorption studies of the structural modifications induced by electrochemical lithium intercalation into V2O5 , 1990 .

[12]  García,et al.  Structure of oriented V2O5 gel studied by polarized x-ray-absorption spectroscopy at the vanadium K edge. , 1989, Physical Review B (Condensed Matter).

[13]  F. Walsh,et al.  Instrumentation and data acquisition for insitu electrochemistry at the Daresbury SRS , 1989 .

[14]  G. Ouvrard,et al.  Redox processes in the LixFeS2/Li electrochemical system studied through crystal, Mössbauer, and EXAFS analyses , 1989 .

[15]  D. Clapham,et al.  G-protein βγ-subunits activate the cardiac muscarinic K+-channel via phospholipase A2 , 1989, Nature.

[16]  W. Heineman,et al.  Development of extended X-ray absorption fine structure spectroelectrochemistry and its application to structural studies of transition-metal ions in aqueous solution. , 1986, Analytical chemistry.

[17]  B. Lengeler,et al.  Extended x-ray absorption fine structure analysis of interatomic distances, coordination numbers, and mean relative displacements in disordered alloys , 1980 .

[18]  M. Stanley Whittingham,et al.  Chemistry of intercalation compounds: Metal guests in chalcogenide hosts , 1978 .

[19]  R. D. Shannon Revised effective ionic radii and systematic studies of interatomic distances in halides and chalcogenides , 1976 .

[20]  E. Stern,et al.  Extended x-ray-absorption fine-structure technique. II. Experimental practice and selected results , 1975 .