Improvement on the Use of Se@C in Batteries by Synergistic Effect of Nano-Confinement and C-Se Bond

Abstract

In order to alleviate the cyclic attenuation caused by the dissolution of poly-selenides in lithium/sodium storage devices, quantitative selenium was slowly evaporated on the surface of sodium citrate derived carbon (SCDC) at low temperature, and simultaneously the element Se was doped. Benefiting from the synergistic effects of the domain-limiting effect of embedded nanopores on Se nanoparticles and the stability of SCDC with Se doped during the embedding and stripping of Na ions, Se@C versus sodium metal exhibits high second specific capacity of 485 mAh·g−1 and unexpected stability at 0.1 A g−1 and 1 A g−1. Se@C versus lithium metal exhibits high second specific capacity of 1185 mAh·g−1 at 0.1 A g−1 and excellent stability. Together with the simple and application of synthesis method, Se@C composite is expected to become an anode material for large sodium/lithium storage devices.