Binding S0.6Se0.4 in 1D Carbon Nanofiber with CS Bonding for High‐Performance Flexible Li–S Batteries and Na–S Batteries

A one‐step synthesis procedure is developed to prepare flexible S 0.6 Se 0.4 @carbon nanofibers (CNFs) electrode by coheating S 0.6 Se 0.4 powder with electrospun polyacrylonitrile nanofiber papers at 600 °C. The obtained S 0.6 Se 0.4 @CNFs film can be used as cathode material for high‐performance Li–S batteries and room temperature (RT) Na–S batteries directly. The superior lithium/sodium storage performance derives from its rational structure design, such as the chemical bonding between Se and S, the chemical bonding between S 0.6 Se 0.4 and CNFs matrix, and the 3D CNFs network. This easy one‐step synthesis procedure provides a feasible route to prepare electrode materials for high‐performance Li–S and RT Na–S batteries.