LDHs derived nanoparticle-stacked metal nitride as interlayer for long-life lithium sulfur batteries.

Shuttle effect is one of the most serious disadvantages in lithium-sulfur battery which results in poor cycle performance and hinders the commercialization of Li-S battery. To reduce the dissolution of polysulfides into the electrolyte and prolong the cycling stability, nanoparticle-stacked metal nitride derived from layered double hydroxides (LDHs) as an interlayer was inserted between sulfur cathode and separator to confine polysulfides by physical and chemical interactions. Meanwhile, the surface of metal nitride will form an oxide passivation layer. The passivation layer possesses hydrophilic metal-O group and provides a polar surface for strong binding with polysulfide. What's more, the nanoparticles-stacked structure could immerge and retain electrolyte well, which could enhance the ability of promoting the electron exchange rate. The sulfur electrode with nanoparticle-stacked metal nitride interlayer has an excellent cycle performance owing to the interactions between metal nitride and polysulfides. The battery delivered an initial capacity of 764.6 mAh g and still possesses a capacity of 477.5 mAh g with the retention of 62.4% after 800 cycles.