Effect of electrochemical cycling on microstructure of sulfur electrodes

Abstract

In lithium–sulfur (Li–S) batteries, during discharge, there is a significant morphology change as solid sulfur (S) gets dissolved and undergoes successive reduction and finally precipitates as lithium sulfide (Li2S) in porous cathode [1]. This also leads to volume change of the electrolyte in the pore space attributed to precipitation/dissolution of the solid sulfur phase. Moreover, due to the changes in the pore volume coming from the hydrostatic pressure induced by the electrolyte, the cathode microstructure shrinks or swells to accommodate these changes [2]. This leads to mechanical degradation of the electrode over cycling. Thus, the electrochemical performance of lithium sulfur battery is strongly affected by the microstructure of S electrode.