Sulfur-Biological Carbon for Long-Life Room-Temperature Sodium-Sulfur Battery

Room-temperature sodium-sulfur (RT-Na/S) batteries are gaining much attention particularly in large-scale energy storage due to high theoretical energy density and low cost. However, low conductivity and volume expansion of sulfur, as well as severe shuttle effect of soluble sodium polysulfides largely hamper their practical applications. Herein, we report an architecture of sulfur embedded in biological carbon (SBC) as cathode for RT-Na/S batteries. The SBC with N, P co-doping biological carbon and hierarchically porous structure afford fast electron and ion transportation, as well as good mechanical limitation of volume expansion and shuttle effect, therefore achieving excellent cyclic stability (544.7 mAh · g –1 at current density of 200 mA · g –1 after 984 cycles).