TiO ₂ ‐Fe ₂ TiO ₅ heterostructure hollow spheres enable high‐performance lithium‐sulfur batteries via interfacial engineering

Abstract

The shuttle effect of lithium polysulfides between sulfur cathode and lithium anode is a notorious problem in the commercial application of lithium‐sulfur batteries. Herein, heterostructured TiO 2 ‐Fe 2 TiO 5 hollow spheres were proposed and synthesized as efficient sulfur host to address the shuttle behavior of polysulfides. TiO 2 ‐Fe 2 TiO 5 hollow heterostructure can not only accommodate sulfur and serve as physical barrier to prevent polysulfides diffusion, but also endow an enhanced absorption ability on polysulfides and accelerated conversion kinetics of polysulfides through the generation of built‐in electric field (BIEF) on their heterointerface. Consequently, TiO 2 ‐Fe 2 TiO 5 @S electrode demonstrates a high initial capacity of 1185 mAh·g −1 at 0.2C, good rate capability and stable lifespan over 500 cycles at 0.5C with a small capacity decay of 0.07% per cycle.