N,O Co‐Doped Carbon Spheres Enable Stable Anode‐Less Sodium Metal Batteries

Anode-less sodium metal batteries (SMBs) suffer from the formation of Na dendrites and inactive Na on an anode substrate though showing advantages of high energy densities and low costs. Herein, N,O co-doped carbon spheres (NOCS), which are synthesized via a scalable polymerization and pyrolysis method, are employed as a thin and stable sodiophillic nucleation layer on the Cu foil. Combined with electrochemical measurements, Na deposition morphology observations and density functional theory calculations, it is revealed that the introduced N and O heteroatoms can greatly enhance the adsorption of Na