Enhanced Chemisorption and Catalytic Effects toward Polysulfides by Modulating Hollow Nanoarchitectures for Long-Life Lithium-Sulfur Batteries.

ABSTRACT

Hollow nanostructures with intricate interior and catalytic effects hold great promise for the construction of advanced lithium-sulfur batteries. Herein, a double-shelled hollow polyhedron with inlaid cobalt nanoparticles encapsulated by nitrogen-doped carbon (Co/NC) nanodots (Co-NC@Co9 S8 /NPC) is reported, which is acquired by using imidazolium-based ionic-polymer-encapsulated zeolitic imidazolate framework-67 as a core-shelled precursor. The Co/NC nanodots promote redox kinetics and chemical adsorbability toward polysulfides, while the interconnected double shells serve as a nanoscale electrochemical reaction chamber, which effectively suppresses the polysulfide shuttling and accelerates ion/electron transport. Benefiting from structural engineering and reaction kinetics modulation, the Co-NC@Co9 S8 /NPC-S electrode exhibits high cycling stability with a low capacity decay of 0.011% per cycle within 2000 cycles at 2 C. The electrode still shows high rate performance and cyclability over 500 cycles even in the case of high sulfur loading of 4.5 mg cm-2 and 75 wt% sulfur content. This work provides one type of new hollow nanoarchitecture for the development of advanced Li-S batteries and other energy storage systems.