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Lithium sulfur (Li-S) batteries demonstrate great promise for efficient energy storage systems once the lithium polysulfide (LPS) shuttling and sluggish redox kinetics can be well addressed.Herein,we developed a sea urchin-structured oxygen-deficient titanium dioxide semiconductor anchored with cobalt nano-dots (Co@TiO2-x) as a high-performance multifunctional sulfur host material for Li-S batteries.The sea urchin-structured Co@TiO2-x offers strong structural stability and strengthened chemical interaction towards LPS.Meanwhile,the incorporation of Co nano-dots into TiO2 leads to increased oxygen vacancies,which augments the electrical conduction and benefits LPS conversion acceleration as well.As a result,the oxygen vacancy-rich Co@TiO2-x composite exhibits excellent conductivity,strong LPS confinement and promoted sulfur electrochemical kinetics,rendering enhanced LPS shuttling inhibition and rapid redox reaction.Attributed to these features,the Co@TiO2-x/S cathode exhibits a discharge capacity of 803 mAh g-1 at 1 C and a good cyclic stability upon 500 cycles with a low capacity fading rate of 0.07％ per cycle.This synergistic design of conductive multifunctional LPS barrier is also promising to enlighten the material engineering in other energy storage applications.