  Due to their high energy density (2600 Wh/kg), low cost, and low
environmental impact, lithium-sulfur batteries are considered a promising
alternative to lithium-ion batteries. However, their commercial viability
remains a formidable scientific challenge mainly because of the sluggish
reaction kinetics at the cathode and the so-called "shuttling effect" of
soluble polysulfides, which results in capacity decay and a shortened lifespan.
Herein, molecular imprinting with Li$_2$S$_8$ as a target molecule in
combination with a two-dimensional material, MXene, is proposed to overcome
these issues. Molecularly imprinted polymer-coated nitrogen-doped Ti-based
MXene was successfully synthesized and demonstrated to exhibit an appealing
electrochemical performance, namely a high specific capacity of 1095 mAh/g at
0.1 C and an extended cycling stability (300 mAh/g at 1.0 C after 300 cycles).
X-ray photoelectron spectroscopy was applied to elucidate the underlying
mechanisms and proved that Li$_2$S$_8$-imprinted polymer polyacrylamide serves
as a polysulfide trap through strong chemical affinity towards the long-chain
lithium polysulfides, while N-doped Ti-based MXene promotes the redox kinetics
by accelerating the conversion of lithium polysulfides. This distinct
interfacial strategy is expected to result in more effective and stable Li-S
batteries.
