Creating Edge Sites within the 2D Metal‐Organic Framework Boosts Redox Kinetics in Lithium–Sulfur Batteries
Xingbo Wang, Xingbo Wang, Chunrong Zhao, Bingxue Liu, Shangqian Zhao, Yongguang Zhang, Lanting Qian, Zhongjun Chen, Zhongjun Chen, Jiantao Wang, Xin Wang, Xin Wang, Zhongwei Chen, Zhongwei Chen
Abstract
Abstract Lithium–sulfur batteries have received extensive interest owing to their exceptionally high energy density. Nonetheless, their practical implementation is still impeded by the shuttle effect of polysulfides and sluggish conversion kinetics. Considering that, a porous 2D defective zeolitic imidazolate framework‐7 (ZIF‐7) with abundant active edges is rationally designed as multifunctional sulfur carriers for Li–S batteries. The 2D ZIF‐7 enables uniform distribution of sulfur and rapid Li‐ion diffusion, while rich edges facilitate sufficient exposure to active sites capturing and catalyzing polysulfides. In addition, the nitrogen defects on edge sites can further accelerate the transformation of polysulfides and decrease the energy barrier of Li 2 S decomposition. Consequently, the Li–S batteries demonstrate surprisingly practical prospects with a stable capacity of 676.9 mAh g −1 over 500 cycles at 1 C (capacity retention rate = 72.3%). When assembled into a pouch cell at 2.3 mg cm −2 , it still exhibits a high capacity of 901.1 mAh g −1 after 100 cycles at 0.1 C. This work offers a rational structural design strategy to tackle the challenges of the sulfur cathode.