Two-dimension Al2O3-AlN heterogeneous nanosheets as bifunctional host materials for kinetics-accelerated and dendrite-free lithium-sulfur batteries.

The polysulfides shuttle and the uncontrolled dendrite growth remain the biggest roadblocks to the extensive application of lithium-sulfur batteries (LSBs). Herein, we propose heterogeneous Al 2 O 3 -AlN nanosheets that rooted on carbon nanofiber film as bifunctional hosts for these troubles, which are prepared by the facile ammonification of two-dimension metal-organic framework MIL-101(Al). As the sulfur host, the Al 2 O 3 -AlN nanosheets exhibit a strong synergistic effect of physicochemical anchoring and outstanding electrocatalysis on polysulfides, which is strengthened by the superiorities of heterostructure. In the meantime, the excellent conductivity and fully exposed Al, N lithiophilic sites guarantee a fast and homogeneous Li deposition, thus suppressing the dendritic growth. Accordingly, with the assistance of these distinctive heterogeneous nanosheets, LSBs provide a striking capacity of 730 mAh g−1 and an outstanding cycling stability with a narrow decay of 0.025% per cycle for 1000 cycles under 5 C, and also excellent cycle and rate properties at high sulfur loadings with a reduced electrolyte. This work offers new viewpoints of heterostructures as both cathode and anode materials for advanced LSBs. [ABSTRACT FROM AUTHOR]