Vertically Oriented Bismuth Selenide with Exposed Crystal Facets as the Sulfur Host for High-Loading Lithium-Sulfur...

The shuttling effect of lithium polysulfides (LiPSs) and sluggish redox kinetics are the primary obstacles hindering the commercial application of lithium-sulfur (Li-S) batteries. Most existing studies on two-dimensional-layered material-based sulfur hosts mainly focus on bulk electronic modulation, ignoring the impact of crystal growth geometry on the electrochemical performance. Herein, we designed carbon-cloth-supported, vertically oriented bismuth selenide with preferentially exposed (006) crystal planes (denoted as v-Bi₂Se₃@CC) as the sulfur host for Li-S batteries. Benefiting from the vertical structure, abundant active sites are exposed and a three-dimensional network is constructed to facilitate efficient mass transport, while the exposed Se active sites on the (006) planes reduce the reaction energy barrier of LiPSs conversion. Consequently, the Li-S batteries assembled with v-Bi₂Se₃@CC deliver a high specific capacity of 1396 mAh g^-1 at 0.2 C, excellent cycling stability with a capacity fading rate of 0.058% per cycle over 500 cycles at 2 C, and a favorable performance even under a high sulfur loading of 11.3 mg cm^-2. This work demonstrates that crystal orientation engineering is an effective strategy to optimize sulfur hosts, providing insights for the development of high-performance Li-S batteries.