ZIF-Derived Carbon Nanoframes as a Polysulfide Anchor and Conversion Mediator for High-Performance Lithium–Sulfur Cells

Improving the redox kinetics of sulfur species, while suppressing the “shuttle effects” to achieve stable cycling under high sulfur loading is an inevitable problem for lithium–sulfur (Li–S) cells to commercialization. Herein, the three-dimensional Zn, Co, and N codoped carbon nanoframe (3DZCN-C) was successfully synthesized by calcining precursor which protected by mesoporous SiO2 and was used as cathode host for the first time to improve the performance of Li–S cells. Combining the merits of strong lithium polysulfides (LiPSs) anchoring and accelerating the conversion kinetics of sulfur species, 3DZCN-C effectively inhibit the shuttling of LiPSs and achieves excellent cyclability with capacity fading rate of 0.03% per cycle over 1000 cycles. Furthermore, the Li–S pouch cell has been assembled and has been shown to operate reliably with high energy density (>300 Wh kg–1) even under a high sulfur loading of 10 mg cm–2. This work provides a simple and effective way for the promotion and commercial application of Li–S cells.