Confined sulfur electrode to achieve quasi-solid state sulfur conversion reaction in Li–S battery

摘要

? 2023 Elsevier LtdAn ordered mesoporous carbon (OMC) inlaid with micropores was derived via a hard template method. OMC micropores loaded with sulfur (S-OMC) were used as a cathode for the Li–S battery. A comparison of UV–Visible analysis of S, S-OMC and S-loaded carbon nanotube (S-CNT) indicated lower solubility of S into the electrolyte from S-OMC. Controlling the solubility of S into the electrolyte is important to reduce the polysulfide concentration in the electrolyte. Cyclic voltammetry and galvanostatic charge-discharge measurements of S-OMC indicated the merging of solid-S → polysulfide and liquid-polysulfide → lower-order lithium sulfide transitions. Instead of the two-plateau discharge curve normally observed in S?carbon composite electrodes, a single sloppy discharge curve was observed with S-OMC. Which possibly due to lower S concentration in the electrolyte, which results in reduced polysulfide concentration and lowers dynamic viscosity of the electrolyte. At 0.2C, nearly 1254 mAh g?1 of capacity was realized with capacity loss 2.2 V in the confined zone. Due to the confinement effect, the growth of Li2S occurs slowly both at the anode and cathode, thereby enabling high voltage and capacity discharge with S-OMC compared to the S-CNT.