Strong lithium polysulfides chemical trapping of TiC-TiO2/S composite for long-cycle lithium-sulfur batteries

In our study, TiC-TiO2/S composite was successfully prepared with a simple and effective method. For this special micro-mesoporous structure, TiC-TiO2 can be used as an efficient sulfur storing material, and also restrain the volume expansion of sulfur to a certain degree for its suitable specific surface area. TiO2 and TiC can suppress the diffusion of polysulfides due to their strong interaction with polysulfides. At the same time, TiC also can remedy the nonconductive defect of sulfur for its good conductivity. With the help of above advantages, the TiC-TiO2/S cathode delivers an initial discharge specific capacity of 1218 mAh g−1 at 1 C (1 C = 1675 mA g−1) with the sulfur loading of 1.5 mg cm−2. And when cycles at 0.5 C, a stable capacity of 714 mAh g−1 can be maintained after 500 cycles accompanied with the sulfur loading of 1.1 mg cm−2.