An innovative electronically-conducting matrix of the cathode for sodium sulfur battery

• Carbon felt good wettable with sodium polysulfides is prepared using hybrid sol.
• Coated carbon felt shows little sulfur on the electrolyte at 100 mA cm−2 on charge.
• Coulombic efficiency of the cell with the coated carbon felt retains above 99.9%.

An innovative electronically-conducting cathode matrix, that makes sodium sulfur (NaS) battery excellent in discharge-charge performance, is prepared by surface modification of a carbon felt with inorganic nanoparticles. A carbon felt is dipped into an inorganic-organic hybrid sol, dried, and heat-treated at 600 °C for 2 h in a flowing argon. Coated surface of the felt has been examined by scanning electron microscopy (SEM) equipped with energy dispersive X-ray spectroscopy (EDX) and scanning transmission electron microscopy (STEM). The cell prepared with the coated carbon felt shows 92% of charge acceptance and 99.9% of coulombic efficiency at 100 mA cm−2 of current density.