X-ray Raman spectroscopy of lithium-ion battery electrolyte solutions in a flow cell

The effects of varying LiPF6 salt concentration and the presence of lithium bis(oxalate)borate additive on the electronic structure of commonly used lithium-ion battery electrolyte solvents (ethylene carbonate – dimethyl carbonate and propylene carbonate) have been investigated. X-ray Raman scattering spectroscopy (a non-resonant inelastic X-ray scattering method) was utilized together with a closed-circle flow cell. Carbon and oxygen K-edges provide characteristic information on the electronic structure of the electrolyte solutions, which are sensitive to local chemistry. Higher Li+ ion concentration in the solvent manifests itself as a blue-shift of both the π * feature in the carbon edge and the carbonyl π * feature in the oxygen edge. While these oxygen K-edge results agree with previous soft X-ray absorption studies on LiBF4 salt concentration in propylene carbonate, carbon K-edge spectra reveal a shift in energy, which can be explained with differing ionic conductivities of the electrolyte solutions.

Source: Journal of Synchrotron Radiation - February 21, 2018 Category: Physics Authors: Ketenoglu, D. Spiekermann, G. Harder, M. Oz, E. Koz, C. Yagci, M.C. Yilmaz, E. Yin, Z. Sahle, C.J. Detlefs, B. Yava ş , H. Tags: non-resonant inelastic X-ray scattering lithium-ion battery electrolyte C and O K-edge spectra research papers Source Type: research