Supporting data for "Cellulose separators with integrated carbon nanotube interlayers for lithium-sulfur batteries: an investigation into the complex interplay between cell components"

This is the dataset of electrochemical experiments for our publication "Cellulose separators with integrated carbon nanotube interlayers for lithium-sulfur batteries: an investigation into the complex interplay between cell components". This archive contains the raw data and scripts written in R used in the analysis and presentation of the results in this manuscript. <strong>Abstract for the manuscript:</strong> This work aims to address two major roadblocks in the development of lithium-sulfur (Li-S) batteries: the inefficient deposition of Li on the metallic Li electrode and the parasitic “polysulfide redox shuttle”. These roadblocks are here approached, respectively, by the combination of a cellulose separator with a cathode-facing conductive porous carbon interlayer, based on their previously reported individual benefits. The cellulose separator increases cycle life by 33%, and the interlayer by a further 25%, in test cells with positive electrodes with practically relevant specifications and a relatively low electrolyte/sulfur (E/S) ratio. Despite the prolonged cycle life, the combination of the interlayer and cellulose separator <em>increases</em> the polysulfide shuttle current, leading to reduced Coulombic efficiency. Based on XPS analyses, the latter is ascribed to a change in the composition of the solid electrolyte interphase (SEI) on Li. Meanwhile, electrolyte decomposition is found to be slower in cells with cellulose-based separators, which explains their longer cycle life. These counterintuitive observations demonstrate the complicated interactions between the cell components in the Li-S system and how strategies aiming to mitigate one unwanted process may exacerbate another. This study demonstrates the value of a holistic approach to the development of Li-S chemistry. Manuscript preprint available at ChemRxiv (pending approval as of 9/7/19).