TiO2 microboxes as effective polysufide reservoirs for lithium sulfur batteries.

Abstract Mesoporous hollow TiO 2 microboxes synthesized by a two-step solvothermal method via CaTiO 3 intermediate were applied as host materials for sulfur cathodes of lithium-sulfur batteries. 3TiO 2 /7S composite containing 70 wt% sulfur exhibited the best electrochemical performance among all composites. A high discharge capacity of 924.8 mAh g−1 was achieved for the 1st cycle and 67.4% of it could be retained after 200 cycles at 0.2 C. Even at a higher C-rate of 1 C, more than 600 mAh g−1 of discharge capacity could be delivered after 500 cycles. The efficient polysulfide adsorption of TiO 2 microboxes demonstrated by visualized adsorption test and UV–vis measurement as well as the mesoporous hollow feature was responsible for the large discharge capacity, excellent capacity retention and decent rate capability. Graphical abstract Image 1 Highlights • Hollow mesoporous TiO 2 microboxes were synthesized. • TiO 2 microboxes exhibited excellent polysulfides adsorption ability. • 3TiO 2 /7S was found to be the best proportion for electrochemical performance. • 626 mAh g−1 of discharge capacity could be delivered after 500 cycles at 1 C. • TiO 2 microboxes were potential candidates for host of sulfur cathode. [ABSTRACT FROM AUTHOR]