Methods—Ampero-Coulometry: A New Technique for Understanding Lithium-Sulfur Electrochemistry. Issue 3 (7th March 2023)

• Record Type: Journal Article
• Authors: Gulzar, Umair; Lonergan, Alex; Egorov, Vladimir; Zhang, Yan; Grant, Alex; Carroll, Aoife; O'Dwyer, Colm
• Is Part Of: Journal of the Electrochemical Society. Volume 170:Issue 3(2023)
• Publication Date: 2023-03-07
• Subjects: Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/1945-7111/acbca0
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Despite limited commercial success, lithium sulfur technology (LST) is still far from competing existing Li-ion technology. One of the main reasons hindering the success of LST is the complexity of lithium-sulfur chemistry during electrochemical charging and discharging. Dissolution of sulfur species in the electrolyte solution exacerbates the difficulties of this system. Therefore, a comprehensive understanding of sulfur species and their kinetics during charge/discharge process is paramount for a high-performance lithium-sulfur battery. We present a new technique we refer to as Ampero-Coulometry, which takes the chronoamperometric (galvanostatic) charge-discharge curves and mathematically transforms them to a series of curves that reveal the cation diffusional rate inside carbon-sulfur porous electrodes at different states of charge/capacity. This technique allowed us to track the overall Li + ion diffusional rate inside a Li-S cell over a complete state of discharge. As dissolution of sulfur species and their interplay inside a porous sulfur electrode has a significant role in limiting Li-S battery capacity, and method allows correlation between the known mechanism of polysulfide dissolution, the kinetics of a sulfur electrode, and its response.