Green and facile fabrication of porous titanium dioxide as efficient sulfur host for advanced lithium-sulfur batteries: An air oxidation strategy.

Lithium-sulfur (Li-S) battery has been considered a promising next-generation electrochemical energy storage device due to its high theoretical capacity and high energy density. However, the dissolution and shuttling problems of lithium polysulfides (LiPSs) are major obstacles hindering the performance and application of Li-S batteries. To address these issues, we report the rapid preparation of porous TiO nanoparticles (p-TiO-NPs) as an effective sulfur host for Li-S batteries using a facile, scalable, and green one-step air oxidation strategy. Experimental results reveal that the p-TiO-NPs have a mesopores-rich structure and strong chemical adsorption capability against LiPSs, which effectively mitigates the dissolution and shuttling of LiPSs by way of physical and chemical adsorptions. Incorporating highly conductive multi-wall carbon nanotubes to interconnect with the active materials, the p-TiO-NPs-based cathode delivers a high discharge capacity of 1276 mAh g at 0.2 C and stable cycling performance with an ultralow capacity decay rate of 0.0526% per cycle at 1 C over 1200 cycles. This green and facile fabrication strategy can also be extended to other metal carbides to endow an environmentally friendly route for the sustainable development of high-performance Li-S batteries.