Temperature-Dependence of the Solid-Electrolyte Interphase Overpotential: Part I. Two Parallel Mechanisms, One Phase Transition
Year: 2018
Type: article
Abstract: It has been shown recently that the overpotential originating from ionic conduction of alkali-ions through the inner dense solid-electrolyte interphase (SEI) is strongly non-linear. An empirical equation was proposed to merge the measured resistances from both galvanostatic cycling (GS) and electrochemical impedance spectroscopy (EIS) at 25°C. Here, this analysis is extended to the full temperature range of batteries from −40°C to +80°C for Li, Na, K and Rb-metal electrodes in carbonate electrolytes. Two different transport mechanisms are found. The first one conducts alkali-ions at all measured temperatures. The second transport mechanism conducts ions for all seven measured Li-ion electrolytes and one out of four Na-ion electrolytes; however, only above a certain critical temperature T C . At T C a phase transition is observed switching-off the more efficient transport mechanism and leaving only the general ion conduction mechanism. The associated overpotentials increase rapidly below T C depending on alkali-ion, salt and solvent and become a limiting factor during galvanostatic operation of all Li-ion electrolytes at low temperature. In general, the current analysis merges the SEI resistances measured by EIS ranging from 26 Ωcm 2 for the best Li up to 292 MΩcm 2 for Rb electrodes to its galvanostatic response over seven orders of magnitude. The determined critical temperatures are between 0–25°C for the tested Li and above 50°C for Na electrolytes.
DOI: 10.1149/2.0701802jes
Author: Michael Hess
Institution: ETH Zurich
Language: English
Subfield: Electrical and Electronic Engineering
Field: Engineering
Domain: Physical Sciences
Open Access status: hybrid
Estimated APC paid: $1,950
Award: G188712115
OpenAlex ID: W2787478149