Excellent sodium storage performance of carbon-coated TiO2: Assisted with electrostatic interaction of surfactants

Abstract To enhance the electronic conductivity of TiO 2 , carbon-coating has been used as a simple and effective method for improving the electrochemical performances of TiO 2 in sodium ion batteries. In this work, considering the internal connection between TiO 2 and the coated carbon-layer, we synthesized carbon-coated TiO 2 composites (TiO 2 /C) via hydrothermal method and subsequent calcination, assisted with different types of surfactant as carbon sources. Due to strong electrostatic attraction, cationic surfactant CTAB (cetyltrimethyl ammonium bromide) generates a uniformly-coated carbon layer onto TiO 2 surface, which enables good electronic conductivity and fast kinetics of the product. Therefore, TiO 2 /C assisted with CTAB as carbon source (TiO 2 /C-C) shows optimal sodium storage performance with excellent specific capacity (303 mA h g −1 at 0.1 C) and satisfying cycling stability, offering promising anode for constructing high capacity sodium ion batteries.