Amorphous Al₂O₃ with N-Doped Porous Carbon as Efficient Polysulfide Barrier in Li–S Batteries

Inhibiting the shuttle effect of polysulfides is one key factor to develop a practically applicable Li–S battery. To overcome the shuttle effect, we developed here an ultrastable Li–S battery with amorphous Al2O3 nanohybrid separator for the first time. Through molecular design of the ligands, the material of the separator from carbonized MOF–Al at elevated temperature is composed of amorphous Al2O3 and N-doped porous carbon, which shows higher electrical conductivity, faster lithium diffusion and charge transfer capability, and stronger interaction with lithium polysulfides through the synergistic effect (MOF, metal–organic framework). The fabricated Li–S battery proposed here corresponds to the lowest capacity decay (only 0.054% of capacity decay in each cycle) as far as we know, which may open up new avenues for developing the next-generation lithium-ion battery.