Investigation of the Effect of Using Al₂O₃–Nafion Barrier on Room-Temperature Na–S Batteries

Room-temperature sodium–sulfur batteries are promising battery systems because of their high theoretical capacity, high energy density, and low cost. However, their application is hindered by several issues, especially linked with the polysulfide shuttle effect. Herein, Al 2 O 3 –Nafion membrane is used to prevent migration of polysulfides from the cathode side to the anode assisting to lessen the active material loss. While Al 2 O 3 is a very effective adsorbent to trap polysulfides anions, Nafion membrane has cation selectivity which permits migration of Na + cations and repels polysulfide anions due to the negatively charged sulfonic groups. Thus, an increase in the performance of room-temperature sodium–sulfur batteries (RT Na–S batteries) is expected by combining their constructive effects. As a result, higher capacity retention is achieved with ∼250 mAh/g capacities after 100 cycles in the presence of Al 2 O 3 –Nafion membrane in contrast to the cell without any interlayer.