TiO₂-Fe₂TiO₅ heterostructure hollow spheres enable high-performance lithium-sulfur batteries via interfacial engineering

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 TiO₂-Fe₂TiO₅ hollow spheres were proposed and synthesized as efficient sulfur host to address the shuttle behavior of polysulfides. TiO₂-Fe₂TiO₅ 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, TiO₂-Fe₂TiO₅@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.