posted on 2024-01-29, 17:08authored byXiaojun Zhao, Yubo Dang, Hongzhou Ma, Panqing Bai, Wangzi Li, Zhi-Hong Liu
Balancing the adsorption of lithium-polysulfide intermediates
on
polar host material surfaces and the effect of their electronic conductivity
in the subsequent oxidation and reduction kinetics of electrochemical
reactions is necessary and remains a challenge. Herein, we have evaluated
the role of polarity and conductivity in preparing a series of ascharite/reduced
graphene oxide (RGO) aerogels by dispersing strong polar ascharite
nanowires of varying mass into the conductive RGO matrix. When severed
as Li–S battery cathodes, the optimized S@ascharite/RGO cathode
with a sulfur content of 73.8 wt % demonstrates excellent rate performance
and cycle stability accompanied by a high-capacity retention for 500
cycles at 1.0 C. Interesting advantages including the enhanced adsorption
ability by the formation of the Mg–S and Li bonds, the continuous
and quick electron/ion transportations assembled conductive RGO framework,
and the effective deposition of Li2S are combined in the
ascharite/RGO aerogel hosts. The electrochemical results further demonstrate
that the polarity of ascharite components for the S cathode plays
a dominant role in the improvement of electrochemical performance,
but the absence of a conductive substrate leads to serious capacity
attenuation, especially the rate performance. The balanced design
protocol provides a universal method for the synthesis of multiple
S hosts for high-performance LSBs.