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

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.