Perfluorosulfonic Acid Membrane for Lithium–Sulfur Batteries with S/C Cathodes

Batteries. 2022. Vol. 8. No. 10. Article 162.

Yaroslavtsev A. B., Novikova S., Voropaeva D., Li S., Kulova T.

Polymer electrolyte based on Nafion-117 membranes in the Li+ form with intercalated
1,3-dioxolane-dimethoxyethane solvent mixtures (DOL-DME) has been obtained. The obtained electrolyte
Nafion-Li+-DOL-DME has been characterized by DSC analysis, IR- and impedance spectroscopy.
The solvent uptake of membrane in the DOL-DME mixture amounts to 1.9. Nafion-Li+-DOL-DME
is characterized by an ionic conductivity ~10􀀀7 S cm􀀀1 at room temperature. The comparative
study of the electrochemical properties of Li–S batteries with liquid electrolyte (1M Li(CF3SO2)2N
in DOL-DME) with polypropylene film (PP) or Nafion-Li+-DOL-DME and S/C composites with
mesoporous carbon as cathode materials has shown that the use of membrane can improve cyclability
of the cell. The first-cycle discharge capacities of S/C electrodes in the Li–S battery cells with PP and
Nafion-Li+-DOL-DME were 730 and 450 mAh g􀀀1, respectively (0.1 mV s􀀀1). However, the discharge
capacity of S/C in the cell with PP reduced significantly after 10 cycles. The Li–S battery with the use
of membrane exhibits significantly enhanced cyclability. The discharge capacity of S/C in the cell
with Nafion-Li+-DOL-DME amounts to 365 mAh g􀀀1 after 10 cycles and to up to 290 mAh g􀀀1 after
40 cycles.

Keywords: conductivity, selectivity, Ion exchange membranes, Li–S battery, solvent uptake