Resol and urea derived N-doped porous carbon for Na-ion storage

We demonstrate a facile tetraconstituent (Phloroglucinol, glyoxal, urea and triblock copolymer Pluronic F127) co-assembly approach to prepare N-doped porous carbon. The N-doped porous carbon has a layer spacing as large as 0.393 nm, a disordered structure and a specific surface area as high as 502 m(2) g(-1), which may boost its battery property. When assembled into Na ion batteries, the N-doped porous carbon delivered a stable capacity up to 229 mA h g(-1) at 100 mA g(-1) after 200 cycles, higher than that (123 mA h g(-1)) of the undoped porous carbon. Furthermore, the initial Coulombic efficiency of the N-doped porous carbon was increased from 21% to 91% by employing ether electrolyte instead of common ester electrolyte, which is because almost neglected solid electrolyte interface film after the first cycle was formed on the electrode. Accordingly, a high capacity over 300 mA h g(-1) was obtained for the first 20 cycles at the same current density.