Open AccessTransmission Line Model Impedance Analysis of Lithium Sulfur Batteries: Influence of Lithium Sulfide Deposit Formed During Discharge and Self-Discharge
Author(s) -
Sara Drvarič Talian,
Gregor Kapun,
Jože Moškon,
Robert Dominko,
Miran Gaberšček
Publication year - 2022
Publication title -
journal of the electrochemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.258
H-Index - 271
eISSN - 1945-7111
pISSN - 0013-4651
DOI - 10.1149/1945-7111/ac4a4e
Subject(s) - cathode , electrolyte , polysulfide , materials science , electrical impedance , capacitance , lithium (medication) , dielectric spectroscopy , sulfide , analytical chemistry (journal) , chemistry , composite material , chemical engineering , electrode , electrical engineering , electrochemistry , metallurgy , medicine , chromatography , endocrinology , engineering
The effect of Li 2 S deposition on the impedance response of Li-S battery cells is investigated using a simplified cell design, systematic impedance spectroscopy measurements combined with transmission line modeling, and a complementary microscopy analysis. Glassy carbon cathodes are employed to build and validate the proposed transmission line model, which is later on employed to investigate the effect of various parameters of Li 2 S deposit (coverage, thickness, porosity) on cell’s impedance. Among others, the model is applied to study the effect of discharge and self-discharge. Finally, the simplified planar cathode is exchanged with a more conventional mesoporous carbon cathode to determine the effect of Li 2 S deposition on the impedance of a commercially viable cell design. We have found that Li 2 S deposit has little effect on the impedance response, owing to its porous structure. The most noticeable change stemming from the process of Li 2 S deposition is due to the depletion of polysulfide species concentration in the electrolyte, which decreases the chemical capacitance and increases the tail height in the low frequency region of the impedance spectra.