Discharge characteristic analysis of lithium-sulfur batteries considering the discontinuous deposit and transport-limited effects
File(s)
Accepted version
Author(s)
Type
Journal Article
Abstract
The modeling research plays a crucial role in grasping the reaction mechanisms and forecasting the performance of lithium-sulfur (Li–S) batteries. A transient Li–S battery model including continuity, transportation, and reaction kinetics by simultaneously considering the discontinuous deposit of discharge product Li2S and the transport limitation in the concentrated electrolyte, is developed to reveal the discharge phenomena. The effects of operating conditions and electrolyte and electrode properties on the discharge behaviors including voltage-capacity curve, energy density, profiles of solid product (ɛLi2S) and porosity (ɛ) at the cathode are quantitatively studied. It is found that low discharge rate is beneficial to the discharge capacity and utilization of cathode sulfur. Enhancing precipitate (S8) solubility Ksp, S8 and ionic diffusivity Di improves voltage plateau and specific energy to varying degrees; the promotion of voltage plateau will be inconspicuous as electrode conductivity σ is enlarged over 0.1 S/m. With the rise of ɛ from 0.5 to 0.9, the specific capacity and the specific energy are expanded by around 5 times. When lengthening Lca from 20 μm to 60 μm, the specific capacity ascends from 944.5 to 991.5 mAh/g-S, whereas the growth rate of specific capacity and specific energy decreases gradually; the practical total energy almost increases linearly with thickness, yielding a 218.75% enhancement. With a certain period of relaxation, the recovered cell capacity after the high discharge rate is higher than that after the low discharge rate. This work may guide in designing electrodes and electrolytes and provide performance regulation strategies for Li–S batteries.
Date Issued
2024-01-10
Date Acceptance
2024-01-10
Citation
Journal of Cleaner Production, 2024, 436
ISSN
0959-6526
Publisher
Elsevier
Journal / Book Title
Journal of Cleaner Production
Volume
436
Copyright Statement
Copyright © 2024 Elsevier Ltd. This is the author’s accepted manuscript made available under a CC-BY licence in accordance with Imperial’s Research Publications Open Access policy (www.imperial.ac.uk/oa-policy)
License URL
Subjects
CAPACITY
Discharge behaviors
Engineering
Engineering, Environmental
Environmental Sciences
Environmental Sciences & Ecology
Green & Sustainable Science & Technology
HIGH-PERFORMANCE
Ionic transport
KINETICS
Li -S batteries
Life Sciences & Biomedicine
Mathematical model
MATHEMATICAL-MODEL
Porous cathode
Science & Technology
Science & Technology - Other Topics
Technology
Publication Status
Published
Article Number
140719
Date Publish Online
2024-01-11