Synergistic effect in the ZIF67-derived core shell structure towards the improved electrochemical performances in lithium-sulfur batteries

Abstract

A ZIF-67 core could be grown within the hollow carbon sphere to further develop the hierarchical core shell structure, which displays synergistic effects as sulfur host in lithium sulfur batteries (LSB). The carbon shell with N active sites exhibits strong anchoring capability towards lithium polysulfide (LiPS), and the electrochemical conversion kinetic is favorably accelerated by the ZIF-67 derived carbon core. By virtue of the unique core shell structure and advantageous active species of the host material, the resulting composite cathode exhibits the high initial reversible capacity of 1308 mAh g−1 at 0.1C and outstanding long-term stability at 2C with a mere 0.039 % decay rate over 600 cycles. This work may shed a light on rational designing of novel sulfur host material towards the synergistic improvement of electrochemical performances of LSB.