Supercritical fluid assisted synthesis of titanium carbide particles embedded in mesoporous carbon for advanced Li-S batteries

Because of high theoretical energy density, low-cost and environmental benignity, lithium-sulfur battery is recognized as a prospective candidate for replacing conventional lithium-ion batteries. However, its large scale commercialization is limited by inherent defects of sulfur cathode such as poor electronic conductivity and polysulfide shuttle effect. Herein, we report that titanium carbide particles embedded in CMK-3 mesoporous carbon (TiC/C) with the assistance of supercritical CO2 fluid is highly effective sulfur host to improve cycling capability and rate performance. Compared with TiO2/C-S and CMK-3-S, the TiC/C-S cathode exhibits higher reversible capacity and better cycling performance. It delivers high specific capacities at various C-rates (866, 622, and 438 mAh g−1 at 0.1, 0.5, and 2 A g−1, respectively) and remarkable capacity retention of 73% (200 cycles at 0.2 A g−1). The excellent electrochemical properties of TiC/C-S can be attributed to the polar nature and high conductivity of TiC particles. The present work provides a novel strategy in synthesizing cathode materials for high performance Li-S battery.