posted on 2021-08-12, 14:33authored byBin Qin, Yifei Cai, Xiaoqing Si, Chun Li, Jian Cao, Weidong Fei, Haijiao Xie, Junlei Qi
The
development of Li–S batteries (LSBs) is largely impeded
by sluggish redox kinetics and notorious polysulfide shuttling. Herein,
hierarchical MoC@Ni–NCNT arrays are reported as a multifunctional
sulfur host in Li–S batteries, which comprised a flexible carbon
fiber cloth substrate decorated with vertical MoC porous nanorods
rooted by interconnected nitrogen-doped carbon nanotubes (NCNTs).
In the designed host, the inner MoC porous backbone (composed of nanoparticles)
along with the in situ-grafted interwoven NCNT shell can greatly maximize
the host–guest interactive surface for homogeneous sulfur dispersion,
thus realizing decent high-sulfur-loading performance. Ni nanoparticles,
encapsulated within NCNTs in the outer shell, act as strong chemical-anchoring
centers effectively trap-escaped polysulfides and propel the bidirectional
sulfur transformation kinetics. In merit of sufficient adsorption
and catalytic sites, the cell configured with the MoC@Ni–NCNT
cathode delivers not only high capacity (1421 mA h g–1 at 0.1 C) but also superior rate performance and ultralong lifespan.
The cell can still achieve a superb areal capacity of 6.1 mA h cm2 under an increased sulfur loading up to 6 mg cm–2. This work could open a new avenue for the construction of a multifunctional
cathode for high-performance LSBs.