Sn Nanoparticles\nEncapsulated in Nanoporous Nitrogen-Rich\nCarbon Derived from Sn-MOF@ZIF‑8 for Lithium–Sulfur\nBattery Separators

Lithium–sulfur batteries (LSBs)\nhave attracted considerable\nattention as high-energy density battery technology for applications\nin renewable energy storage and electric vehicles. However, challenges\nsuch as low sulfur conductivity and the polysulfide shuttle effect\nmust be addressed. In this study, we prepared C–N/Sn with nanoporous\nchannels using Sn-MOF@ZIF-8 as a precursor. The resulting C–N/Sn\nmaterial has highly dispersed Sn nanoparticles encapsulated in nitrogen-rich\ncarbon with a three-dimensional continuous conducting framework. During\nthe preparation process, tin oxides were reduced to elemental Sn nanoparticles,\nwhile the decomposition of the ZIF-8 skeleton and the volatilization\nof most of the Zn resulted in the formation of nanoporous channels,\nwhich facilitates the transport of Li ions and electrons while inhibiting\npolysulfide shuttling. The C–N/Sn separator battery exhibited\nan initial discharge specific capacity of 925 mAhg<sup>–1</sup> at a sulfur loading of 2.8 mg cm<sup>–2</sup> and 0.5 C current\ndensity, which remained at 515 mAh g<sup>–1</sup> after 500\ncycles. Furthermore, it also demonstrated good cycling performance\nat a higher sulfur loading condition of 5 mg cm<sup>–2</sup>, highlighting its potential for commercialization.