A Facile Synthesis of Stable TiO₂/TiC Composite Material as Sulfur Immobilizers for Cathodes of Lithium–Sulfur Batteries with Excellent Electrochemical Performances

Abstract

At the moment, sulfur immobilizers for lithium–sulfur batteries have been extensively studied. Herein, a facile synthesis of stable TiO 2 /TiC composite materials as sulfur immobilizers for cathodes of lithium–sulfur batteries is shown; the conductivity of TiC and strong adsorption of the Ti—O bond on sulfur in TiO 2 are combined together to achieve excellent conductivity and effectively inhibit the shuttle effect of polysulfides. X‐ray diffraction, scanning electron microscopy, and Raman spectrogram peak tests show that the TiC surface is successfully coated by a layer of TiO 2 with a stable structure and excellent porosity. Physical and chemical adsorption of sulfur hosting with the TiO 2 /TiC composite material is formed by a hot‐melting method. Electrochemical performance tests show that when the proportion of sulfur hosting is 55%, the cathode has better reversibility, lower charge transfer impedance, and higher lithium‐ion diffusion rate. Charge and discharge results prove that the specific capacities are 1044.68, 870.62, and 696.06 mAh g −1 at 0.1, 0.2, and 0.5 C, respectively, and after 400 cycles, the capacity retention rate is over 50%. This proves that TiO 2 /TiC composite materials are well‐suited to act as sulfur immobilizers for lithium–sulfur batteries.