Improving salt-to-solvent ratio to enable high-voltage electrolyte stability for advanced Li-ion batteries

O. A. Drozhzhin, V. A. Shevchenko, M. V. Zakharkin, P. I. Gamzyukov, L. V. Yashina, A. M. Abakumov, K. J. Stevenson, E. V. Antipov

Research output: Contribution to journalArticlepeer-review

14 Citations (Scopus)

Abstract

High-voltage stability of LiBF4 - propylene carbonate solutions in intermediate concentration range is studied by means of cyclic voltammetry, galvanostatic cycling and X-ray photoelectron spectroscopy using LiCoPO4 and LiNi0.5Mn1.5O4 cathode materials. Coulombic efficiency improves with increasing salt-to-solvent molar ratio from 1:12 to 1:4 (∼0.8 m–2.5 m solutions), reaching 98% at 1C charge/discharge rate for 1:4 electrolyte upon cycling of LiNi0.5Mn1.5O4 up to 5 V vs. Li/Li+. The same positive trend is observed for discharge capacities, cycling stability and capacity scattering for both high-voltage cathode materials. X-ray photoelectron spectroscopy of the electrodes studied after cycling in solutions of different concentrations does not reveal any drastic difference in surface composition. Interface pre-formation experiment shows that the presence of the interface layer formed at semi-concentrated 1:4 electrolyte does not have a major impact on the electrochemical properties of the dilute solution. We assume that the enhanced oxidation stability of the concentrated solutions itself is a reason of improving the electrochemical performance rather than the cathode-electrolyte interface properties.

Original languageEnglish
Pages (from-to)127-133
Number of pages7
JournalElectrochimica Acta
Volume263
DOIs
Publication statusPublished - 10 Feb 2018

Keywords

  • Concentrated electrolyte
  • High-voltage electrolyte
  • Li-ion batteries
  • LiBF
  • Propylene carbonate

Fingerprint

Dive into the research topics of 'Improving salt-to-solvent ratio to enable high-voltage electrolyte stability for advanced Li-ion batteries'. Together they form a unique fingerprint.

Cite this