Na2S–Carbon Nanotube Fabric Electrodes for Room‐Temperature Sodium–Sulfur Batteries

Abstract

A unique sodium sulfide (Na₂S) cathode is developed, which will allow the use of sodium-free anodes for room-temperature sodium–sulfur (Na–S) batteries. To overcome the “inert” nature of the Na₂S, a special cathode structure is developed by spreading the multi-walled carbon nanotube (MWCNT)-wrapped Na₂S particles onto MWCNT fabrics. Spectroscopic and electrochemical analyses reveal a series of polysulfide intermediates involved in the charge/discharge of the cell. The Na–S battery prepared in full discharge state with the Na₂S/MWCNT cathode provides a remarkable capacity of 500 A h kg⁻¹ (based on sulfur mass) after 50 cycles.