Lithium Ion Conducting Boron-Oxynitride Amorphous Thin Films: Synthesis and Molecular Structure by Infrared Spectroscopy and Density Functional Theory Modeling
Artikel i vetenskaplig tidskrift, 2013

Li ion containing oxynitride amorphous thin films are promising materials for electrochemical applications due to their high ionic conductivity, mechanical stability and chemical durability. Here we report on the preparation of Li boron-oxynitride (LiBON) amorphous thin films by rf sputtering of Li-diborate and Li-pyroborate targets in nitrogen atmosphere. The materials produced were subsequently studied by infrared transmittance spectroscopy assisted by density functional theory calculations using representative Li boron-oxide and boron-oxynitride clusters. The combination of experiments and calculations allows us to propose accurate vibrational assignments and to clarify the complex infrared activity of the LiBON films. Both experimental and calculated spectra show that nitrogen incorporation induces significant structural rearrangements, manifested mainly by a change in boron coordination number from four to three, and by the formation of boron-nitrogen-boron bridges. The nature of boron-nitrogen bonding depends on the composition of the sputtering target, with an exponential relationship adequately describing the dependence of B-N stretching frequency on bond length. Besides bonding to two boron atoms by covalent bonds, the nitrogen atoms interact also with Li ions by participating in their coordination sphere together with oxygen atoms. Likely, boron-nitrogen bonding in LiBON films facilitates Li ion transport due to induced charge delocalization within the boron-nitrogen-boron bridges and reduced electrostatic interaction with the Li ions.

electronic-structure theory

crystal

raman-spectroscopy

ray photoelectron-spectroscopy

phosphate-glasses

phosphorus oxynitride

electrolytes

oxygen bond distances

borate glasses

structure

electrical-conductivity

Författare

M. Dussauze

Institut des Sciences Moleculaires, Talence

Theoretical and Physical Chemistry

E. I. Kamitsos

Theoretical and Physical Chemistry

Patrik Johansson

Chalmers, Teknisk fysik, Kondenserade materiens fysik

Aleksandar Matic

Chalmers, Teknisk fysik, Kondenserade materiens fysik

C. P. E. Varsamis

Theoretical and Physical Chemistry

D. Cavagnat

Institut des Sciences Moleculaires, Talence

P. Vinatier

Institut de Chimie de la Matiere Condensee de Bordeaux

Y. Hamon

Institut de Chimie de la Matiere Condensee de Bordeaux

Journal of Physical Chemistry C

1932-7447 (ISSN) 1932-7455 (eISSN)

Vol. 117 7202-7213

Styrkeområden

Energi

Materialvetenskap

Ämneskategorier

Den kondenserade materiens fysik

DOI

10.1021/jp401527x