In Situ Conversion of Metal–Organic Frameworks into VO<sub>2</sub>–V<sub>3</sub>S<sub>4</sub> Heterocatalyst Embedded Layered Porous Carbon as an “All‐in‐One” Host for Lithium–Sulfur Batteries
Seung‐Deok Seo, Seungho Yu, Sangbaek Park, Dong‐Wan Kim
Abstract
Abstract Although lithium–sulfur batteries exhibit a fivefold higher energy density than commercial lithium‐ion batteries, their volume expansion and insulating nature, and intrinsic polysulfide shuttle have hindered their practical application. An alternative sulfur host is necessary to realize porous, conductive, and polar functions; however, there is a tradeoff among these three critical factors in material design. Here, the authors report a layered porous carbon (LPC) with VO 2 /V 3 S 4 heterostructures using one‐step carbonization–sulfidation of metal–organic framework templates as a sulfur host that meets all the criteria. In situ conversion of V–O ions into V 3 S 4 nuclei in the confined 2D space generated by dynamic formation of the LPC matrix creates {200}‐facet‐exposed V 3 S 4 nanosheets decorated with tiny VO 2 nanoparticles. The VO 2 /V 3 S 4 @ LPC composite facilitates high sulfur loading (70 wt%), superior energy density (1022 mA h g −1 at 0.2 C, 100 cycles), and long‐term cyclability (665 mA h g −1 at 1 C, 1000 cycles). The enhanced Li–S chemistry is attributed to the synergistic heterocatalytic behavior of polar VO 2 and conductive V 3 S 4 in the soft porous LPC scaffold, which accelerates polysulfide adsorption, conversion, and charge‐transfer ability simultaneously.