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Modeling the effect of key cathode design parameters on the electrochemical performance of a lithium‐sulfur battery
Author(s) -
Erisen Nisa,
Emerce Nur Ber,
Erensoy Sevgi Can,
Eroglu Damla
Publication year - 2018
Publication title -
international journal of energy research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.808
H-Index - 95
eISSN - 1099-114X
pISSN - 0363-907X
DOI - 10.1002/er.4045
Subject(s) - cathode , electrolyte , electrochemistry , chemistry , analytical chemistry (journal) , battery (electricity) , lithium (medication) , cell voltage , materials science , chemical engineering , electrode , thermodynamics , chromatography , physics , medicine , power (physics) , engineering , endocrinology
Summary A 1D model is developed for the Li‐S cell to predict the effect of critical cathode design parameters—carbon‐to‐sulfur (C/S) and electrolyte‐to‐sulfur (E/S) ratios in the cathode—on the electrochemical performance. Cell voltage at 60% depth of discharge corresponding to the lower voltage plateau is used as a metric for calculating the cell performance. The cathode kinetics in the lower voltage plateau is defined with a single electrochemical reaction; thus, the model has a single apparent kinetic model parameter, the cathode exchange current density ( i 0,pe ). The model predicts that cell voltage increases considerably with increasing carbon content until a C/S ratio of 1 is attained, whereas the enhancement in the cell voltage at higher ratios is less obvious. The model can capture the effect of the C/S ratio on the cathode kinetics by expressing the electrochemically active area in the cathode in carbon volume fraction; the C/S ratio in the cathode does not affect i 0,pe in the model. On the other hand, the electrolyte amount has a significant impact on the kinetic model parameter such that increasing electrolyte amount improves the cell voltage as a result of increasing i 0,pe . Therefore, in the model, i 0,pe needs to be defined as a function of the electrolyte volume fraction, which is known to have a crucial effect on reaction kinetics.