A Liquid Inorganic Electrolyte Showing an Unusually High Lithium Ion Transference Number: A Concentrated Solution of LiAlCl4 in Sulfur Dioxide

Energies

Robert Hartl²  Matthias Fleischmann¹  Ruth M. Gschwind¹  Martin Winter³ 

[1] Institute of Organic Chemistry, University of Regensburg, 93040 Regensburg, Germany; E-Mails:;Workgroup Electrochemistry and Electrolytes, Institute of Theoretical and Physical Chemistry, University of Regensburg, 93040 Regensburg, Germany; E-Mail:;Münster Electrochemical Energy Technology (MEET) Battery Research Center, Institute of Physical Chemistry, University of Münster, Corrensstr. 46, 48149 Münster, Germany; E-Mail:

关键词: lithium ion transference number;    lithium tetrachloroaluminate;    sulfur dioxide;    Hittorf’s method;    diffusion-ordered spectroscopy (DOSY)-NMR;   

DOI  :  10.3390/en6094448

来源: mdpi

【 摘 要 】

We report on studies of an inorganic electrolyte: LiAlCl₄ in liquid sulfur dioxide. Concentrated solutions show a very high conductivity when compared with typical electrolytes for lithium ion batteries that are based on organic solvents. Our investigations include conductivity measurements and measurements of transference numbers via nuclear magnetic resonance (NMR) and by a classical direct method, Hittorf’s method. For the use of Hittorf’s method, it is necessary to measure the concentration of the electrolyte in a selected cell compartment before and after electrochemical polarization very precisely. This task was finally performed by potentiometric titration after hydrolysis of the salt. The Haven ratio was determined to estimate the association behavior of this very concentrated electrolyte solution. The measured unusually high transference number of the lithium cation of the studied most concentrated solution, a molten solvate LiAlCl₄ × 1.6SO₂, makes this electrolyte a promising alternative for lithium ion cells with high power ability.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.