Dual-porosity carbon derived from waste bamboo char for room-temperature sodium-sulfur batteries using carbonate-based electrolyte

Room-temperature sodium-sulfur (RT Na-S) batteries have recently drawn a great deal of attention owing to their low cost and high theoretical energy density, making them promising energy storage systems. In this study, a dual-porosity carbon (DPC) matrix with oxygen-containing functional groups derived from waste bamboo char was synthesized by a facile chemical activation for RT Na-S batteries. A high initial discharge capacity of 1168 mAh g−1 at 0.1 C and a superior capacity retention of 320 mAh g−1 at 0.5 C over 600 cycles were obtained. The excellent electrochemical performances came from the unique porous structure and oxygen-containing functional groups of DPC. These properties combined physical and chemical methods to anchor polysulfides and further enhance the electrochemical performance. This study has great significance in terms of building a relationship between waste biomass and electrochemical materials, providing low-cost, green, and sustainable development of advanced energy materials in the future.