Suppressing Polysulfide Shuttling and Enhancing Reaction Kinetics of Lithium–Sulfur Batteries through the Architecture of a 3D TiO 2 @CMK-3 Composite Cathode

Lithium–sulfur batteries (LSBs) have garnered attention recently owing to energy density and ecological sustainability. Nevertheless, commercialization is hindered by key challenges, including yields, polysulfide shuttling, fast capacity fade, and sluggish kinetics. Herein, a 3D TiO 2 @CMK-3 composite cathode is designed and fabricated so as to promote the overall performance of LSBs. The interconnected, conductive, and porous architecture of ordered mesoporous carbon CMK-3 can provide physical confinement for sulfur species and establish efficient ion/charge transport pathways. Meanwhile, the deposited TiO 2 particles exhibit strong chemisorption toward lithium polysulfides for redox conversion. Density functional theory (DFT) and molecular dynamics simulation show that TiO 2 @CMK-3 can better facilitate ion/charge transfer and anchor polysulfides for redox reactions. Besides, the additives LiNO 3 and LiTFSI in the electrolyte can also better weaken the Li + solvation and suppress the lithium polysulfide shuttle. At 0.1C, the as-prepared Li 2 S/TiO 2 @CMK-3 cathode initially releases 946.9 mAh g –1 . Consequently, the application of a three-dimensional network carbon coating with transition metal oxides could be an available strategy for the industrialization of LSBs.