The
modification of separators with transition metal compounds
is an effective strategy to alleviate the shuttle effect of polysulfides
in lithium–sulfur (Li–S) batteries. Herein, a novel
interlayer on the separator was designed and prepared by employing
Cr-based compounds (Cr2O3 and Cr3C2), favorable sulfur host materials, as a polysulfide
anchor for promoting rate capability and cycling life. Thanks to its
specific bonding in the crystal structure, enhanced lithium-ion diffusion
dynamics, and better confine function with soluble polysulfides, the
Cr3C2-modified separator exhibits an improved
electrochemical performance as compared to the Cr2O3-modified separator, including a high capacity of 544 mA h
g–1 at 5 C, a good capacity retention ratio of about
53.3%, and excellent cycling stability with a low decay rate of 0.063%
per cycle at 3 C. It is believed that the positive outcomes will shed
light on carbide as a potential competitor for adsorbing polysulfides,
as well as supply a facile and effective avenue for expediting practical
applications of Li–S batteries.