Potassium hydroxide activated carbon derived from albumen as an efficient sulfur host for room temperature sodium-sulfur batteries

Abstract

The room temperature sodium–sulfur (RT/NaS) battery provides a potential energy storage technology with high theoretical capacity and low cost. However, the gap between its practical performance and theoretical expectation confines its comprehensive implementation. In this work, a simple annealing process successfully synthesized a hierarchical micro/mesoporous egg carbon with KOH activation (ECK) from albumen as sulfur hosting for RT/NaS batteries. KOH activation plays a vital role in enhancing conductivity, surface area, and porosity. Elemental sulfur was loaded to the ECK through simple heat evaporation to form an ECK@S composite. Even at the high rate of 1 C, the discharge capacity of the ECK@S electrode reached 473 mAh/g and maintained 202 mAh/g after 800 cycles, representing an outstanding performance. Therefore, preparing micro/mesoporous egg carbon by KOH activation creates a promising electrode material for RT/NaS batteries.