The Role of Current Collector in Enabling the High Performance of Li/S Battery

Abstract

Among several factors, the nature of the current collector plays a significant role in determining the performance of Li/S battery. Carbon-based substrates gained recently increasing interest as alternative to conventional aluminum substrate. We show herein that cells based on sulfur-graphene composite reveal higher reversible capacity and lower polarization using carbon-based support rather than the typical aluminum current collector. The enhancement of cell performances is attributed to a decrease of electrode-electrolyte interphase resistance promoted by the use of carbon-support, as detected by electrochemical impedance spectroscopy (EIS) upon cyclic voltammetry (CV). This beneficial effect is ascribed to an improved contact of the active material particles with the support, and to increased electrode/electrolyte wetting due to its porosity and chemical nature, which are detected by Hg porosimetry, N2 adsorption/desorption isotherms, SEM and X-ray photoelectron spectroscopy (XPS). Therefore, the results reported in this work may be of interest for setting-up the most suitable condition for achieving high performance Li/S battery